Crimson Oath

by Cassie Swindon

** A gothic romantasy with enemies to lovers, mythical creatures, and steam for 18+ set in nature settings with modern vibes*

A soul-sucking demon & her hunter, forced to work together.
Ryker doesn't even know Crimson is a Slynik, a monster of midnight known to lurk between shadows. Yet, he despises her anyways.

Crimson is well aware that Ryker wants her and her entire species dead, but she must partner with him to find what she's looking for.

Genres: Fantasy

418 pages, Kindle Edition

Expected publication May 4, 2026

About the author

https://linktr.ee/CassieSwindon

Reviews

[Alex · Rating 2 out of 5]

ARC received from the author:

I enjoyed many parts of this book, such as the relationship between sisters, the interesting magic system, and the way that these demons sustain their life.

I am not a fan of books written in present-tense, so I would keep this in mind if you have similar preferences. This book is also written in first-person, switching between the main characters

Regrettably, it seemed that the character backstories and relationships were not fully formed or described. The relationship between the main characters was both drawn-out and very abrupt. The two main characters are older (not teens or early 20s), but the way they behave in the story is very immature.

There is a mention of the loss of a pregnancy during the story, but I felt no emotion connection to it because it felt like an afterthought that was added to give a character more trauma. In fact, while I love most of the tropes used, many of the tropes in this book seemed to be included to appeal to more readers rather than moving the story along or actually enhance the reading experience.

Much of the book felt more like the story was being told to us, rather than showing and immersing the reader in the story. Additionally, there are portions of the story which indicate that this takes place in a future magical dystopia; however, the story does not elaborate on the deeper impact the history of the dystopia causes.

I truly wanted to enjoy this story more, and while the book was not not necessarily my preference, I can certainly understand why so many other ARC readers have enjoyed it.

[Warboss Mad Sam · Rating 2 out of 5]

I received an advanced copy for an honest review. I had to stop this at 33%.

I LOVE the premise of this novel. LOVE the idea of it. It was fresh and interesting and I was so here for it!

I liked all the ideas surrounding the post apocalyptic style world, the banning of books and technology, the illiterate MMC. chefs kiss. The premise was set up to be something beautiful.

I didnt like the pacing. it felt forced and weird. MMC and FMC interactions felt fake, not real. Felt forced. Their silly tiff in the beginning wasn't dramatic or dynamic enough for their encounters to be the way they were. A lot was left to be desired. I really wanted to like this book. But it just kinda felt rushed and awkward between the main characters. The MMC was very clearly written by a woman, you know? He didnt feel like a MAN to me.

I definitely tried. I wanted to put it down before 33%. I promised an honest review. Thank you for letting me try for you.

[Alisha · Rating 5 out of 5]

This was incredible! I don't think I've read anything with something remotely similar to the Slyniks and I was thoroughly invested in every aspect.

I loved Crimson and Ryker and the banter between the two the whole time, even if it was because they despised each other.

The whole premise of a mystical elixir that could either kill all Slyniks or get rid of what makes them monsters was amazing too! I thoroughly recommend this book. There was so much I loved and so much I was expecting!

[Rebecca Sørensen · Rating 4 out of 5]

⭐⭐⭐⭐
Imagine Princess Bride but fantasy in a unique, mysterious and fun romantasy with a strong main character and bonds that transcend simply romantic love.

The pros:
🌍 The concept of the world is really fascinating! A world where books are banned and creatures lurk in the night? Yes please! It's not terribly elaborated, but I don't feel like it was missing for me, at least.
👭🧍‍♀️: The sisterhood was great. I loved the devotion Crimson had to her sisters, and I adored the internal struggle she felt between family vows and loyalty versus personal morals.
👩‍🦳🧑‍🦳 I love that it's an older main romance, without the whole 'inexperienced in life' dynamic. They both have lived lives, regrets and balance that makes them feel real. I love how devoted they feel to one another. Who doesn't like a man on his knees?
👩 In general, I really loved the characters, especially Crimson. She feels dynamic, questioning what she's in. She's strong and badass without feeling like a Mary-Sue. She makes mistakes, acts reckless, owns her flaws and I swallowed her chapters!
📝 Which brings me to the writing. I loved that their chapters felt so different. He was brutish while she was more flowery in her thoughts and the words used. It made it easy to distinguish who was taking the lead when. It melted more together the later we got in the book, but whether it was an intentional ingenious to showcase them finding more common ground or pure coincident, I have no idea. I loved it though!
⛰ I'm a sucker for travel books. I love witnessing relationships evolve as they trek through mud and dirt.
🐈‍⬛ Books immediately get better with animal companions. And Milo felt like an essential part, not just thrown in there for laughs. He fought, he supported them, he was a goofball chasing smoke clouds. Love you Milo, 10/10 best character in the entire book.

Cons:
Now to the parts I struggled a bit more with. It might be personal preference and I do feel like a lot of the things got better down the line, but the first half of the book stumped me at times.
💘 The initial attraction felt very off-putting to me, especially considering Ryker's past. I liked that it felt more evened out later, but initially, it smacks you in the face how attracted they are to one another and lusts for one another. Ryker, after a specific scene early on, pretty much feels heed over heels for Crimson for a few chapters which was- very icky to me. It felt sort of like getting whiplash from him missing his dead wife, to lusting for Crimson suddenly.
🚑 He forgives her incredibly fast, where I might have wanted more angst, more conflict, more internal struggling. I think that's a general issue I have with Ryker, however. He feels inconsistent as a character, which is annoying, cause I quite liked him being unique compared to the usual 'brooding and aggressive' type.
😵‍💫 At times it could be fairly fast during the action scenes and a bit confusing? I found myself rereading parts to see if I'd missed something. It could be hard to follow at times, with new action happening rapidly. It also felt like the resolution was too easy, especially regarding the sisters becoming human despite them just draining a whole lot of people, which should have made them more warped.
💔 It sometimes felt like things were added in, but not truly used. It was a shame, because those subjects could most certainly have been developed more on.

Overall, still a really good read! If you like romantasy with a dynamic romance and a brilliantly made main character, I think you'll like this book a lot! I struggled with the first half which took me far too long to read, but the second half I devoured in a day.

[aa dubsea · Rating 2 out of 5]

Review of advance copy received from Author

I want to preface this review by saying I usually read books that are 500+ page standalones, or multi-book series, so my opinions and critiques are absolutely influenced by this preference.

Let's start with what I enjoyed:

- I found the use of lexicon as the representation of a person's soul (called cruxel in the story) genuinely original and poetic. It was a take on auras and souls I haven’t encountered in any other novel.

- I liked the relationship the FMC has with her sisters. There's a fierce kinship there that makes the FMC more relatable.

- I really enjoyed Milo for the simple reason that I'm a sucker for familiars in stories; he helped to highlight the conflict between the MMC and FMC.

- I thought the world was interesting - the dichotomy between the FMC seeing, feeling, and tasting each person’s lexicon and living in a world that has banned written language was compelling.

Here's what I didn't like so much:

- The world was severely underdeveloped and inconsistent. We’re told the story takes place sometime in the future and that books, computers, tablets, and knowledge are banned. Yet we’re never told why or when exactly this shift occurred. Humans still seem (though it’s never clarified) to live in regular houses, towns, and cities (with the exception of the Lanuri, who are ironically not illiterate like the rest of the world). I remember wondering how people make money, operate stores, or even have music, if only a few people can read or write. Those who are literate are members of a secret Codex Op society, but they don't run society. I'm not saying it's impossible to have a modern society without written language, but it has to be intricately designed and thoroughly explained, and neither is done in this story.

- For me, the pacing was extremely difficult to cope with. I prefaced this review with saying I'm used to reading longer standalones or series because I'm used to sinfully drawn out slow burns and fully fleshed enemies to lovers stories. Again, for me, this was not even close to a slow burn (they admit their attraction within their first interaction) nor was it a true ETL. The MMC had a hatred towards the FMC's kind (Slynik), which he didn't even know she was until halfway through the book. The circumstance of them working together as forced colleagues is believable and can explain their initial animosity, but this is not enemies to lovers. It's hermits who begrudgingly have to work together. The rest of their "romance" is very cat and mouse, and they end up essentially in a marriage ceremony so they can maybe have access to Lanuri information, but this all seems to happen within the first few days. Again, pacing was hard to track.

- The plot feels rushed through conflict after conflict after conflict, but not in a methodical or developmental way. At one point, a thousand deadly spiders appear seemingly out of nowhere. Both the FMC and MMC are caught completely unawares, the FMC dies, and is then resurrected using the Elixir they’ve been hunting for all along (which was actually found by her sisters, who seemed to locate it almost immediately while searching for her). How do thousands of spiders simply appear without explanation?

- There were some minor grammar and syntax errors, which is just a pet peeve of mine for any book that is traditionally published. I still don't understand how it can happen; people are literally paid to make sure it doesn't, yet here we are.

I don't know. It felt like the story was trying to hit too many tropes at once, and none were fully fleshed out, resulting in uneven execution.

My bottom line:

I really wanted to like this for the first few reasons mentioned about what I enjoyed (mainly the intrigue of the cruxel and lexicon). In the end, though, I felt the romance was too rushed, and therefore unbelievable. There was too much conflict that felt inserted rather than earned, which really detracted from the story - it felt like conflict for the sake of conflict rather than actually developing the plot or characters.

[Grace Fonseca · Rating 4 out of 5]

Title: Crimson Oath
Author: Cassie Swindon
Pages: 377
Received: ARC given by Author for honest review
Publish Date: May 4, 2026

Summary:

A soul-sucking demon & her hunter, forced to work together.
Ryker doesn't even know Crimson is a Slynik, a monster of midnight known to lurk between shadows. Yet, he despises her anyways.

Crimson is well aware that Ryker wants her and her entire species dead, but she must partner with him to find what she's looking for.

Review:

This is one fantastic ride. I literally could not put his book down. I really fell in love with both of the main characters, Crimson and Ryker. Crimson and Ryker really shouldn’t work but this enemies to lovers really does work because of what both characters have gone through in their lives.
One of the things that works is that they are both determined individuals to find the exact same thing but for very different reasons. They are quite frankly different species. One is a Slynik who has to feed on souls to keep her youth. She didn’t ask to be born this way and wants to stop doing it. She finds out about a Elixir that could cure her and her sisters. Also love the reasons she is doing it. Plus the fact that she has sisters to think about. They have a really interesting relationship there. Its one of the better ones that I have seen.

The backstories are very important to understand both Ryker and Crimson’s past. This plays a huge part of who they are. I really like that we also get Ryker’s backstory and why he is so determined to get rid of the Slynik’s once and for all. His hatred makes him more bullheaded in some ways. Plus his curse makes it hard for him to do the things he needs to do. Plus he has lost a lot. Not to mention the women he loved to one of these creatures. Everything he is doing for a purpose. His ability to read has been lost as part of his curse. This of course changes when he meets Crimson.
The world building is something that I feel like could have been better done. We are in a world where we are deprived of technology and books are rare to find. I felt like we are kind of isolated by Crimson’s comfort and Rykers discomfort. Both also have different class backgrounds you could say. They find an old library and the man who runs it but both are struggling to find books that have knowledge about this elixir. Also later on we find that there is a group run by a side character who becomes one of the people with his own goals. I just felt like we didn’t really see enough of a world without technology.
Both Ryker and Crimson realize that to find this elixir, they will have to work together to find it and get it. Then the adventure really begins. They encounter so many things and find out things about each other. There are so many twists and turns in this book that you really don’t see coming. Plus they realize that things are not what they seem. Both of them start to fall for each other, which is bound to happen.
I do like the development of the plot twist in this book. The last part felt like a rollercoaster of emotions, surprise, oh no moments. Things that happened in the past, and present that Crimson & Ryker were not aware of. Of course, one of these involved one of Crimson’s sisters. I tell you this book got wild and I very much liked the way this book unfolded.
I would recommend this book to readers who like enemies to lovers with unexpected twist. Solid romance and quest book.

Rating:
4 Stars

[Brandy · Rating 5 out of 5]

This book gets a good solid 4.5 stars from me

I first read this book early on and I enjoyed it. If you want dystopian style world with a MMC who will protect those that he loves and a MFC who wants to better her future, then look at this book.

We have our MFC, Crimson who is not what she might seem on the outside. She wants to live a better life for herself and her sisters but doesn't want to keep living the way that she has been told she needs to in order to survive. When she is at the library, she gets introduced to our MMC, Ryker. They are paired on a mission to try and uncover special pieces to try and figure out a puzzle. I don't want to say too much because I don't want to give all the details away. Now with our MFC, she can do some special things. She also steals our MMC motorcycle in the beginning of the book so it is really an enemies to lovers trope. In more ways than one. So as the story progresses, they are at a waterfall and come across a new character. Do we trust this character??? Yes, no?? We shall see. There is adventure and a nice little furry friend to our MMC. Ok, well more than a little furry friend. Read the book, and you will see. The cavern scene is probably my favorite part of this book and I couldn't put it down at this point. We find out that the love our MFC has for her sisters is a struggle at time and as the story progresses, we learn more about this dynamic.

Overall, I thoroughly enjoyed this book. I would recommend it to anyone that wants a MMC that will fight for what he feels is right and protect those that he loves. A MFC who wants to change for the better and is something that is not what should be..... Just read the book and trust me. This comes out right away with what our MFC is and the reason things happen the way that they happen.

Grab this book for a great dystopian world story with some twist and turns..... And one that you won't see until it gets there.

Thank you to the author for allowing me to read this book before it's published. Highly enjoyed the story.

[Charlee · Rating 2 out of 5]

The premise — a dystopian enemies-to-lovers romantasy featuring a soul-sucking demon and her hunter — reads like the kind of thrilling, dark fantasy tale that could really work. The cover art and blurb promise tension, chemistry, and an edgy romance. Unfortunately, for me, the execution fell flat. I can normally finish this size novel in about 2-3 days... this one took me a week and I had to force myself to keep picking it up and reading, while concurrently reading a few others in the interim because this one could not keep my interest.

The pacing felt uneven and often rushed, as if the author was ticking off a trope checklist instead of developing the story organically. Battles, emotional reveals, and supernatural elements zoom past without giving the reader time to feel them, and many classic enemies-to-lovers beats (like real conflict, layered tension, or believable growth) feel half-baked or glossed over.

I didn’t buy the chemistry between the main characters. It felt forced and awkward rather than a compelling descent from mutual distrust to something deeper. Rather than watching two people clash and grow into lovers, it felt more like watching two strangers awkwardly be put together, with minimal justification for the emotional shift. Additionally, the spicy elements felt unwarranted and needless... more like the author just wanted to have a spicy rating so she through them in there without any regard to them adding anything to the story.

The sisters — who are ostensibly the emotional and narrative core for the female main character — feel sidelined. Though they’re clearly meant to motivate the FMC, when they appear their story feels brief and disconnected, almost like an afterthought. Their contributions take on a pointless quality instead of enriching the plot or the protagonist’s motivations.

If you were hoping for an enemies-to-lovers arc that actually feels earned, or deeper integration of key motivations beyond surface tropes, you might be disappointed — as I was. This story had great bones on paper but the execution didn’t deliver for me.

[Sara · Rating 3 out of 5]

I was genuinely excited about this premise, and in the opening chapters I was devouring the pages almost as hungrily as Crimson devours the words of her victims. The concept of souls as cruxes, something intertwined with knowledge and language, rare and consumable, felt original and poetic. There’s something deeply compelling about treating words as both power and sustenance, and those early chapters carried a sharp, intriguing energy.

However, as the story unfolded, it became harder to ignore what felt absent.
The novel leans into a dystopian framework: a future where knowledge and technology are banned. On paper, that’s an incredibly strong foundation. But I found myself craving more depth and clarity. How has it reshaped daily life beyond the surface? The world feels sketched rather than built, like the scaffolding of something fascinating that never fully solidifies. For a premise so rooted in the power of knowledge, the lack of detailed world-building felt like a missed opportunity.
That said, Crimson and her sisters are a highlight. Their dynamic carries warmth and sharpness in equal measure, grounding the story in something emotionally tangible. The sisterhood adds relatability and texture that the broader world sometimes lacks.

I also struggled with the romantic arc. The book seems to promise an enemies-to-lovers dynamic, but to me it read more as strangers-to-lovers. The tension never quite reached the level of true opposition or emotional friction that makes that trope so satisfying. I wanted sharper edges, more conflict, more resistance before surrender.

Overall, I would still recommend this to readers looking for an accessible fantasy with a fresh conceptual twist and lighter world-building. The core idea is genuinely interesting, and while it didn’t fully deliver on its potential for me, I can see it resonating with readers who prefer character focus over intricate dystopian detail.
It’s a new take — one I truly wanted to love

[Blair · Rating 4 out of 5]

Crimson Oath is a moody, gothic, and honestly might be where the world is headed in terms of education if people don't get it together spin on vampires and vampire hunters. The world setting that Cassie Swindon created for this book is incredible and fresh and was a nice break from my normal fantasy world building books. The twist on the typical vampire also had me not able to put the book down!

From the beginning of this book, I knew we were going to be on a journey with Crimson. I did not expect just how emotional and deep that journey would be. I sob cried right along with her when her heart broke over her sisters, when she thought she had lost her found family forever, and when she realized she was ready to give it all up to make the world better.

******
If I concentrate, I can feel them trying to break free, like their sharp nails are clawing at my ribcage to escape. I need to stop our rituals. Something has to change.
******
******
It's not that I want to die. But recently, I no longer want to live forever either. humans have the gift of limited time. Each day is precious because it can't be relived.
******

Then we have Ryker. Oh my sweet, broken, tattered soul and heart Ryker. I loooovveeee when one character doesn't know something life altering about another and they still end up down bad for each other, and Ryker did not disappoint. My dude has so much healing that needs to happen, but he still is funny, charming, and maybe a little insane? But like, aren't we all?

******
If you're a monster, you're my monster."
******

I still have so many questions about things that happened in the book, which is why this one got four stars from me. But if you want a book on vampires that isn't just blood sucking and killing, then this is it.

All thoughts and views are my own.

[Kristin B · Rating 5 out of 5]

***A Dark, Intoxicating Quest for the Heart***

I did not mean to read this in one sitting. That was not the plan.

Crimson is a soul sucking demon who gets roped into working with her enemy to find a legendary elixir. Ryker is the brooding human she would want to drain ... if there wasn't something so different about him.

That sounds like a pretty standard romantasy setup, but this book does it uniquely well. The quest actually feels urgent — there's a real sense that things will go very badly if they don't find the elixir in time — so it never felt like the plot was just an excuse to get the two of them alone together. (Even though it kind of is. And I loved it.)
The romance is a slow burn in the best way. Crimson and Ryker spend a good chunk of the book being difficult and guarded with each other, and it's so satisfying to watch that slowly crack. Their banter is genuinely funny at times. When things finally shift between them it feels earned rather than rushed.
The gothic atmosphere is done really well too — dark forest, an unsettling magic system, a general feeling that something is always slightly wrong. It's creepy without being horror.
My only complaint is that a couple of the side characters felt underdeveloped, but honestly that's a minor gripe. Overall this was exactly what I wanted — a dark, romantic fantasy with a heroine I actually liked and a love interest worth the wait.
Highly recommend if you're into gothic romantasy or just need a book that will make you forget you have responsibilities.

Great for fans of enemies-to-lovers, dark fantasy settings, and slow-burn romance.

[Lexi Nunez · Rating 3 out of 5]

MY FIRST ARC REVIEW:

This book is a solid 3.5 out of 5 stars for me.

I absolutely devoured this book to be honest. I loved the plot, enemies to lovers, and the world. You have the FMC who wants better for herself, sisters, and the world then the MMC who protects those he's loves and will do anything for them. The tension in this book between the two main characters is CHEF'S KISS and the banter, got to love!

Crmison is a soul sucking demon who basically wants to not soul suck anymore. Her sisters love it because it keeps them immortal, but she despises it and wants to stop due to feelings of the humans just living their life. She then meets Ryker, who is the slaying hunter that wants revenge for his Partner (which you'll find out about later). Crimson meets him and finds him intriguing because he is different than the others she's encountered. Not going into to much detail, they both work together to find a "potion" to help them both. They go through this book finding clues and battles to get what they need. It ends up being an enemy to lovers' journey and finding themselves along the way with a little banter in it. The ending of this was just right.


The only thing I have to say is I wish it would've been more world building and possibly a 2-book series or a longer one? I definitely think we could've gotten a whole thing on the world in this book, and it would've been great BUT I will say it was still a good book. I feel like this would be a good book for someone dipping their toes into the fantasy section.

Thank you, Cassie, for letting me be a part of your journey.

[Sheena Concordia · Rating 4 out of 5]

Review of advanced copy received from author.

I want to start off by saying that there was a lot that I enjoyed in this book. The post apocalyptic world where knowledge and technology are banned was interesting especially since the FMC, Crimson, is a vampire of sorts and instead of draining blood drains a persons words and knowledge in order to refrain from aging. She’s very powerful and a total baddie who is easy to like.

The MMC, Ryker, has an interesting backstory about coming from a community that values knowledge but now he is searching for an elixir that will eliminate all of Crimson’s kind. After being cast out of his community following the death of his partner he loses the ability to read as punishment.

When Ryker and Crimson come together it is to search for the mysterious elixir that they believe will do two different things; one believes it will eliminate all of Crimson’s kind while the other believes that it will eliminate the need to drain people’s life.

The magic system is really interesting and I like how it ties together the FMC and the MMC. The story is fast paced and ends on a high note.

Now for the things I didn’t love….

I felt that the story was too short. I would have like to have a little more world building to understand the lack of knowledge. I felt that there were times that things felt rushed and I would have like it to move at a different pace that felt more natural rather than a mad dash to the end.

The FMC and MMC were not exactly enemies to lovers since Ryker didn’t find out about Crimson before he started to develop feelings for her. I would have really liked a little more building of their relationship throughout the book.

[Jenna Robinson · Rating 5 out of 5]

✨ARC Review✨
⭐️⭐️⭐️⭐️💫 (4.5 stars)
🌶️🌶️.5

This book had me completely tangled in tension from the very first page. The enemies-to-forced-allies (and then to lovers) dynamic between Crimson and Ryker was delicious. Every glare, every sharp word, every reluctant moment of teamwork felt like it could snap at any second.

Knowing Crimson’s secret while Ryker hunted her kind added this constant ache under every interaction. I was on edge the entire time, waiting for the truth to explode between them. And the slow burn 🔥 God, it was agonizing in the best way. Every almost-touch, every charged stare lingering a second too long, every moment where hatred blurred into something far more dangerous…it built so naturally and so painfully. You could feel the shift happening inch by inch, even as neither of them wanted to admit it.

Crimson’s quiet strength and Ryker’s conflicted intensity made their connection feel earned. It wasn’t rushed. It wasn’t easy. It was layered with mistrust, fear, and undeniable pull…which made the sparks between them even hotter when they finally flared 🥵

The chemistry, the danger, and that simmering, slow unraveling between hunter and hunted? Completely worth it.

Cassie has a way of drawing you in and wanting more. If you love morally gray tension, hidden identities, and a romance that burns low and slow before it ignites…this one will absolutely sink its claws into you!

[Courtney Joly · Rating 3 out of 5]

❤️‍🔥 ARC Review — 3.5 ⭐ | 🌶 1 Spice
Crimson Oaths by Cassie Swindon

Crimson Oaths is a standalone fantasy that delivers cozy, feel-good vibes while still carrying meaningful stakes.

Told in dual POV (which I loved), this story gives us soft enemies-to-reluctant-allies energy… with the quiet possibility of something more simmering beneath the surface. The tension builds gently and naturally, keeping the romance present but never overpowering the plot.

One of the standout elements was the unique magic system — it felt refreshing and unlike anything I’ve read recently. There’s also a really fun literary aspect woven into the story that added an extra layer of depth. It was creative, captivating, and made the world feel even more immersive.

The high stakes revolve around a riddle that could either save or doom them all, which kept me intrigued throughout. There are twists along the way — a few genuinely caught me off guard.
And Crimson? Her brave heart made her easy to root for from the very first chapter. She felt grounded, determined, and relatable in a world filled with uncertainty.

If you’re looking for:
✨ Standalone fantasy
✨ Dual POV
✨ Soft enemies to allies
✨ Unique magic + literary elements
✨ Low spice / plot-focused romance
✨ Cozy fantasy vibes with stakes

Then this one is definitely worth checking out.
Please give Crimson Oaths a read and let me know your thoughts! 📚✨

[Literary Purrception · Rating 3 out of 5]

***ARC Review***

I am very thankful to have received an ARC of Crimson Oath because the premise sounded really good. Evil/murderous creature + her hunter = winner in my eyes. I really enjoyed the unique various aspects of this story; more specifically about Slyniks and their powers. The whole idea around their abilities, cruxels, the auras, the words that flow from people, etc was really intriguing.

I do wish there was more relationship building and world building. The relationships, specifically as time went on, felt underdeveloped romantically and between sisters. I did read the prequel stories about the three sisters before I read this, so I did have some of the history, I can’t say it was substantial and overall, lacked a bit of relevance for the main book in my opinion.

Additionally, I struggled with the pacing. I will say that I have been tired and sometimes it is more difficult for me to get invested in a book when I get like that. But the first 60% or so of the story felt to be pretty slowly paced and then picked up to slow back down again. It didn’t help, and as much as I wanted to connect and get super invested in this, it just fell short.

Overall, I would still recommend it. If given the chance for a redo I would still choose to ARC read it knowing what I know now. Reading is a unique journey and just because I did not personally get invested in a story; it doesn’t mean you won’t.

[Tiffany aka Chai Tea And Books · Rating 4 out of 5]

🌶️🌶️


Ohhh if you are looking for a true enemies to lovers romantasy, you need to check this one out. This was full of intrigue, danger, and lies. Never mind the sparks flying between the two main characters whether they were battling or kissing 😅 It was a world that I haven't read anything quite like it before, so it was intriguing. It is full of magic and magical creatures, and set in a world that has outlawed knowledge, the written word, and books. It took a little bit to catch on to all of the new terms and beings, but it was a really good read!

❤️ Tropes ❤️
💋 romantasy
💋 enemies to lovers
💋 forced prox
💋 dangerous quest
💋 animal sidekicks

Crimson is tired. Honestly, if she can't find this elixir she doesn't know what to do. She has been writing letters to someone who has been helping her trying to decipher the clue she has to where it is. When she goes to research at the secret library in town, she finds the book she's looking for. Only she isn't the only one wanting it. And this man? He is willing to try and get her kicked out. The owner of the secret library has one solution. They have to work together to find the elixir. Only Crimson is the very thing this man hates. She is the monster they are looking to eliminate. Only according to her research, it could make her and her sisters immortal without having to unalive anyone. And only one of them can be right. Even if she manages to hide her true self from him while they search, which theory will be correct if they find it? But it is a risk Crimson is willing to take.

[FictionHealsMe · Rating 4 out of 5]

Review of an advance copy received from the author.

I was really drawn to the premise of Crimson Oath. A world where all written language is banned and destroyed and people can no longer read is such a fascinating idea. It felt fresh and different right from the start.

Crimson is not human but a Slynic. Her ability to kill by touching someone’s temples and absorb all the words from their soul is a truly unique concept. She was feisty and strong, and this was one of the most interesting parts of the story. It made her character stand out immediately.

Ryker is a human who hates Slynics and wants to wipe them out, which sets up what should be an enemies to lovers dynamic. While there is tension between them, it did not fully feel like true enemies to lovers, but their interactions were still engaging.

Where the story fell a bit short for me was the worldbuilding and pacing. Some parts were exciting and hard to put down, while others felt slower and dragged. There was a lot happening at once, which made some moments feel rushed and not fully developed.

Overall, Crimson Oath has a very original idea and some strong moments, but it needed more depth to fully shine. Still, it was an enjoyable read, and I am glad I picked it up.

[Tiana jenelle · Rating 3 out of 5]

I received this arc (advanced reader copy ) in exchange to give an honest review on what I thought of the book !


I rate this book 3.5 ⭐️ stars

Crimson and her sisters are slynicks, powerful immortal beings who feed off of humans souls aka “cruxel” which is the words spoken in their lifetime. Which I found very intriguing, a very unique take that I have never seen in a book before. They are in a world where the written language is banned and knowledge is basically power. I will say I’m a sucker for a backstory and with this we don’t know the reason behind the purge of technology and why reading and writing is banned in this world it just happened one day.

The dynamic between the FMC and the MMC didn’t feel natural to me. It felt very rushed and forced. And he acted like a child at some points and it wasn’t a vibe. I found it hard to get thru the first 40% of the book.

Now I really did enjoy the story I think the world is interesting the magic system is very unique something we have never seen in a book before and I love it . I just wish there was more world building, more yearning , and just more in general it left alot of questions unanswered for Me and just fell short .

[Bernadett Muller · Rating 4 out of 5]

I was lucky enough to be chosen to be an ARC reader of this great book.
When writing this review I try to be mindful not to spoil the whole story and still give my honest feedback about it. All in all I recommend reading Crimson Oath!

One of my favourite part of the story that it has a very unique world build where written language has been eradicated and it is against the law to own, see or get in contact with anything written.
This builds an exciting background to introduce our MMC who is from a tribe who still values and knows the written words but he isn't with his people any more...
The magical abilities for a certain humanoid creature, Slynik is intriguing as they see kind of auras around people built from their vocabulary they learnt during their lives.
The more educated the person, the more elaborate words they compiled in their lives make them the most delicious to catch in a world where written world is prohibited.

The only reason I've give 4 star out of five is because I would have loved a bit more about the world. How does everything work, how people trade in other parts of this world. How justice served and what rules do they live by if nothing has been written. So many questions and so many opportunity to make it a series :)

[Blitheroo · Rating 4 out of 5]

Overall, this was an incredibly unique read with amazing world-building and so many creative elements I've never read before! The Slyniks are kind of soul-sucking vampires, sustaining themselves by feeding on the aura of humans, but it comes in the form of words. And in a dystopian world where the written word is outlawed, knowledge is power.

Crimson lives with her sisters, all Slyniks. But she's trying to change the world on her own. She's tired of being a predator, tired of buying her immortality with the lives of humans. Ryker is an outcast human who hunts Slyniks because they've destroyed his entire life, taken everything from him. All with the help of his best friend, Milo, the jaguar.

They have an instant chemistry, but it's a slow-burn forbidden attraction and hidden identity. Sooooo good!!! Plus some great twists I didn't see coming!

The only thing that kept this from being 5 stars for me was needing more background and a clearer timeline. I feel like we jumped around a bit and it took me a minute to figure it out. I also feel like Ryker's personality mellowed out faster than I expected, but overall this was a great story! Thank you for this arc opportunity!!

[Nathalie · Rating 4 out of 5]

Very entertaining book with a fast paced storyline and newly interpreted magical creatures.
The "monsters" in Crimson Oath are similar to Succubi or vampires, except for life energy or blood, they are sucking their victims out for words, which is a very interesting twist to classical fantasy creatures.
Furthermore, the family dynamics of both main characters (her sisters, his parents) show families with different values and world views internally.

The reason for me to not give 5 stars is the lack of explanation of how the world came to be as it is in the book. It seems that the world before the Purge was similarly to our world, with smartphones and advanced technologies. What I missed was a short explanation where the magic in this world comes from. I learned there are prequel short stories, that have more explanation, but I still think a bit more information on that topic would have been helpful in this book.

Nonetheless, I can highly recommend this book to all fantasy lovers that also like a good enemies to lovers romance sprinkled in and who are tired of commonly used mythical creatures.

[Leah Marie · Rating 4 out of 5]

This was my first time reading Cassie Swindon, so I went in with no expectations — and came out completely hooked.

I was instantly drawn in by the originality of the characters, especially the dynamic between the two leads. Their relationship felt layered and real, full of sharp banter that had me laughing one minute and deeply emotional the next. The way their story unfolded carried me through every high and low without ever losing momentum.

Fantasy is still a relatively new genre for me, but I’ve discovered I love stories that feel magical while still being grounded in something familiar — worlds that mirror our own just enough to feel possible. This book struck that balance beautifully, blending imaginative elements with relatable emotions and experiences.

The romance was perfectly paced, with just the right amount of spice — enough to add depth and tension without overwhelming the story. It enhanced the connection between the characters rather than overshadowing it.

Cassie Swindon has officially become a new favorite author of mine. I’m genuinely excited to dive into more of her books and experience more of the worlds and characters she creates.

[Cassie · Rating 3 out of 5]

Overall, I thought this book was okay, earning about 3.5 out of 5 stars. One of its most unique and interesting aspects was the concept of the “vampires” stealing language instead of blood to drain people. This twist felt original and added an intriguing layer to the story that helped it stand out from more traditional vampire narratives.

The main plot itself was solid and engaging enough to follow, but the book as a whole did not feel fully polished. Some moments lacked refinement, and this was especially noticeable toward the end. The final chapter before the epilogue felt awkward and did not land with the intensity it seemed to be aiming for. What was meant to be a “spicy” or emotionally charged moment instead came across as uncomfortable, largely due to dialogue that felt out of character and unnatural.

While the book had a strong and creative premise, its execution sometimes fell short. With more refinement—particularly in character interactions and emotional payoff—it could have been much stronger. Despite its flaws, the originality of the concept makes it worth reading, even if it does not fully deliver on its potential.

[Sam Yaworski · Rating 5 out of 5]

This was such a unique and intriguing book. Reading the prequel piqued my interest and I was so excited to ARC read this book! Learning about Slyniks and the Lanuri who hunt them was so fascinating. I greatly enjoyed Crimson's point of view and the use of less common vocabulary to show the vast variety of words she's absorbed through people's cruxels. I understood the Slyniks as if they are word Succubi who get younger after each victim. Crimson was such a loveable character and I love nothing more than a happily ever after. Ryker definitely grew on me as the book progressed, but not Johnathan. After that ending I know why I didn't like him lol. Overall this was a captivating gothic fantasy romance with unique a premise and some words I had to look up and it went so well with the main plot that I just absolutely loved it. I highly recommend this book and I hope to read more in this series or in another collection by this author. Thank you for the opportunity to read this amazing book!

[Danni Drummond · Rating 4 out of 5]

Crimson Oath
By Cassie Swindon

Dark Gothic Romantasy
One touch and you ☠️
Enemies to lovers
Mythical Creatures
Soul sucking demon × demon hunter
Nature setting with modern vibes


This book has left me speechless, I'm not sure i have read anything quite like it but it had me hooked.

This follows the tale of Crimson a demon who sucks the souls from people but in the unique way of words, all the words they have learned throughout their lives? Yep that's how their souls are sucked out. Except Crimson is different, Crimson has grown a conscious and knows deep in herself there has to be another way to survive and stay immortal without continuously hurting people, that's when she learns of an elixir  that could change everything. Only issue is, someone else is hunting for the same elixir with the belief it could be used to wipe her kind out. So which is the truth, and who will find it first?

This was told in such a gripping way! Such a unique story i could not get enough and read it almost in one sitting.

[Ashly · Rating 3 out of 5]

I received an advance reader copy of this book and am leaving this review voluntarily.

This dystopian romantasy offers a unique and deeply personal take on soul/spirit with delightful animal companions that added charm. There are many elements to love, but the dystopian premise initially drew me in.

The biggest drawback is actually that this is a standalone novel - I found myself wanting more! There’s so much potential depth, I could absolutely have seen this as a longer, more expansive series.

I wouldn’t really categorize this as enemies to lovers, more like reluctant allies, but both characters are enjoyably cantankerous. There is instant attraction balanced with believable reasons to resist. That said, both characters show some emotional immaturity, and I think additional development would have strengthened their arc.

Overall, this is an enjoyable story with strong concepts and plenty of room for expansion - whether by Cassie Swindon or in the reader’s imagination. I’d recommend this to someone who enjoys a unique take on the world with light romantic tension.

[Melissa Dodson · Rating 4 out of 5]

I received Crismon Oath as an ARC reader and am leaving my honest review.

Firstly, this book premise was amazing. I loved the new idea and such a different way one could be a succubus! I just ate it up! The concept! The characters! The ingenuity! I am a sucker for something I have never read before and Cassie brought something new to the table and I am here for it. I am a lover of leaving a 5 star read and if this book hadn’t left me wishing for some much more it could have got it.

I found that the concept of enemies to lovers a bit of a stretch. Forced proximity seems more accurate than anything. This book left me wanting more. More story, more background, more character development, and the need for answers. I walk away needing this to be a duology at minimum and a series at best! It felt like the story was forced to fit in this one book when it had the potential to be so much more.

I would recommend this book to anyone looking for such a genuinely new idea! I was captivated by a new world full of new ideas

[Chelsea · Rating 4 out of 5]

I love Bookstagram for many reasons, but mainly because it leads me to books like this. I’m so glad I signed up for this one and had the chance to read it for an honest review.

This was my first book by Cassie Swindon, and it won’t be my last.

In this gothic romantasy, we meet Crimson (it’s literally in the title 😉), a Slynik, aka a soul-sucking demon. Once she feels a soul, resisting it isn’t exactly easy. She’s been alive for centuries, living and feeding alongside her sisters, but she’s starting to question whether this is all there is for her.

The world itself is in a strange place after something called The Purge, no technology, education is banned, and society feels stripped down and fragile.

Enter Ryker: tattooed, illiterate, and very much raised to hate everything Crimson is… even though he doesn’t know she’s a Slynik. The two are forced to work together on a mission neither of them expected, and what starts as tension slowly builds into something deeper. I really enjoyed their banter and the enemies-to-lovers progression.

I don’t often read dystopian, but I thought this was solid. The pacing could’ve been tighter, and I would’ve loved a bit more world building, but overall it was a steady, enjoyable read.

[Jessica Hunneyman · Rating 4 out of 5]

Crimson Oath is a Gothic romantasy, that pulls you in fairly quickly. I loved the ingenuity of a Slynik, who sucks souls but really devours their words. I love how Crimson is fighting between her love for her sisters and her morals. She ends up on a journey to find a magickal elixir, hoping to solve all her problems and in the process crosses paths with Ryker. He is also on the hunt for the elixir (for opposite reasons), but is a Slynik hunter. He lost his partner to a Slynik and is on a war path of destruction. While they each keep secrets from the other, they do end up relying on each other more and more. They are forced to face their pasts in hopes of a brighter future. I do feel it was a bit rushed and could have benefited better as a duology, so we got more of some of the side characters throughout. Otherwise a very unique story and completely worth the read.