Of Sinful Secrets: A Dark Gothic Demon Romance

by Killian Wolf

I took my vows to cleanse my soul. But a deadly sin followed me in.
Asmodeus is Lust incarnate. Now he slips into my room every night, testing how far I’m willing to go before I break.

He knows things about me I don’t understand.

The darkness I’ve only seen in visions, the parts of myself I begged God to take.

Now the priests I trusted are hiding sins far darker than mine.

And I have to decide if Asmodeus came to damn me…

or awaken what has always been mine.


Fans of Sierra Simone’s Priest and Laura Thalassa’s The Four Horsemen series will be drawn into this dark, seductive tale of sin, temptation, and forbidden desire.

286 pages, Kindle Edition

Expected publication July 20, 2026

About the author

Killian Wolf is a Miami, FL native who enjoys pirates, rum, and skulls as much as she loves writing about dark magick and sorcerers. She holds a Bachelor of Arts degree in Cultural Anthropology and Sociology and a Master of Science in Environmental Archaeology and Palaeoeconomy.

Killian writes books about obtaining magickal powers, and stepping into other dimensions. She lives in England with her husband, a tornado of a cat, and the most timid snake you'd ever meet.

When she isn't writing, you might find her at an Archaeological dig, rock climbing, or sipping on dark spiced rum while working on a painting.

Reviews

[RoseLabyrinth Reviews · Rating 5 out of 5]

I received an advance review copy for free, and I am leaving this review voluntarily.

⚠️Content Warning⚠️: This book contains dark themes, medieval brutality, power imbalances, and explicit sexual content involving clergy and a demon. Please check the content warnings on the author's website before reading.

First Impression: I was immediately hooked by the premise, which promised a dark, seductive twist on witchcraft and Christianic blasphemy. Going in, I was incredibly curious to see how the author would handle the dynamic of a devout FMC crossing paths with a demon, and it absolutely delivered on that dark, suspenseful vibe.

My Reactions & Emotions
Perfect Dark Blasphemy: From the very beginning, the narrative fully leans into its dark religious themes. Watching the FMC struggle to reconcile her desperate need to salvage her soul with the intense supernatural pull of the MMC is both heartbreaking and incredibly compelling to read.
Intense Anxiety and High Stakes: The overarching plot is genuinely gripping and kept my heart pounding. The pacing ramps up beautifully, throwing the characters into unexpected danger that forces them to rely on each other in ways that kept me completely on the edge of my seat.
Obsessive Devotion: The devotion is so strong in this installment. Seeing the characters develop such an intense, all-consuming connection where they practically worship each other was easily my favorite dynamic.

What I Loved
Satisfying FMC Growth: I loved watching the FMC's journey as she attempts to escape her family's dark origins. Seeing her grow, embrace her own hidden power, and finally come into her own was deeply rewarding.
Vengeful Satisfaction: The story tackles some incredibly dark corruption, specifically within the secondary villains. Watching those genuinely evil characters finally get exactly what was coming to them was incredibly satisfying.
Top-Tier Explicit Spice: The physical chemistry is steaming hot and perfectly fits the dark paranormal setting. The narrative balances heavy sadomasochism and forbidden pleasure flawlessly, making it a standout for fans of authors like Sierra Simone or Laura Thalassa.

Overall, this is a beautifully seductive, dark tale that perfectly balances an anxiety-inducing plot with steaming hot spice. It is an absolute must-read that I would gladly revisit again!

[Heather Palmer · Rating 5 out of 5]

3.5-4/5 🌶

4.5 (rounded up)/5 ⭐

**MAKE SURE YOU READ THE TRIGGER WARNINGS!!** The following TW's were taken directly from the book.

Torture, brutality, explicit sexual content, insinuations of SA involving minors (not by FMC or MMC), non-consensual sexual contact, non-consensual to consensual sexual contact, power imbalance within the sexual content, and religious trauma.

Sacrilegious themes such as, sex between a demon and nun, direct challenges to religious doctrine and imagery.

I honestly didn't know what to expect with this book, but it definitely exceeded my expectations. I read the blurb for this book but it did not prepare me for the gasp I gusped within the first 3 chapters. There is a really good balance of the dark themes of this book and the lighter themes.

The FMC has great emotional intelligence, which I love and appreciate. She works through questioning religion beautifully. She is smart, headstrong, and she doesn't act impulsively when she's emotional. The MMC is a demon king. This book depicts 'Satan' as a council and I really liked that, I don't think I've ever read a book with anything similar. The 7 deadly sins make up that council and their main objective is to contain evil, not release it.

I will be purchasing a physical copy for my trophy and will be re-reading and annotating like a psycho.

READ THE BOOK!! YOU WILL NOT BE DISAPPOINTED!!

I received an advance review copy for free, and I am leaving this review voluntarily.

[Xavi · Rating 4 out of 5]

It took me a little while to finish this one, only because the start felt a little slow to me and didn't hook me like I'd hoped. Initially, I felt the chemistry between the leads was lacking and, to be frank, I was bored by it. The MMC was definitely alluring and the FMC was fascinating on her own but once they were in the same room together things just felt flat. That said, I am really glad I stuck with it. It may have just been my overly fussy brain when it comes to spice but once the main plot started ramping up, everything else fell into place beautifully. By the time I was about 40% in I was invested. The main plot itself had me by the neck, I was intensely curious about what the heck was going on and while I felt a little underwhelmed here and there, for the most part, I enjoyed it! Sidebar - I LOVED the setting, by the way, it really fed the atmosphere. Very much oozing dark Gothic charm... I would give this book an honest 3.5 stars and a generous 4 if you don't mind the chemistry taking a minute to get where it's going. Definitely recommend this one for the readers that like a demon MMC....

I received an advance review copy for free, and I am leaving this review voluntarily.

[C.J. Piperata · Rating 5 out of 5]

I received an advanced copy of this book and am gladly leaving a review! First of all, we got some serious peppers 🌶️ going on. Lots of spice! But that’s not actually why I couldn’t put the book down…. It was intense. The characters are great. The pace didn’t stop, except for the occasional spicy breather…and the plot was so engaging. Hook after hook and so many mysteries to be solved. Also, if you like demonology— this story does an amazing job with the world building and lore. It’s consistent with demonic mythologies, and well researched. The entities Wolf weaves in are both mythological AND original… one of them actually quite terrifying lol
It’s totally twisted but in the best way!!
Chastity is a nun with a mysterious past, and an even more mysterious destiny. She unravels a compelling scandal and teams up with the most unlikely allie to bring justice to the REAL monsters of the world. And she discovers some amazing power along the way.
Highly recommend!

[Cat B. · Rating 4 out of 5]

Firstly, there are trigger warnings for a reason. It would be awful if someone did not take them into account and rated the book on what they felt were over the top scenarios. This is a very spicy book, and the theme may not be for everyone. However you feel about that, there is no denying that it is very well written as all of Killian's are. You get a good feel for the characters and who they are. In the end, you may even like them. Charity turns out to be a very strong female lead and she definitely comes into her own when all is said and done. Asmodeus comes by his title of Lust Demon honestly, he is exactly that. The real villains of the tale are are the worst of the worst and their sins need to be dealt with according to their severity. You will have to read the story to see what becomes of them.
I received a copy of this book via the author and I voluntarily leave my opinion of the tale.

[ashlee · Rating 5 out of 5]

🖤ARC REVIEW🖤

Title: Of Sinful Secrets
ARC Provided By: BookSirens & Killian Wolf
Release Date: 07|20|2026
Genre: Dark Demon Romance
Rating: ⭐️⭐️⭐️⭐️⭐️
Spice: 🌶️🌶️🌶️
Book Type: Standalone

This was such a fantastic read. The flow of this story and character development was great. The amount of spice that was added was out in perfect timing with everything as well.

I enjoyed watching the FMC trying to decipher between good and evil/right and wrong. While she battled her past, our demon MMC helped her realizes she could be more than what she is. I enjoyed the ending also. It was an extremely well written book with a good plot. I’d definitely recommend adding this to your TBR!

Thank you to BookSirens and Author Killian Wolf for the arc ebook. All thoughts in this review are my own.

[Kayla · Rating 5 out of 5]

"Pray your little heart out, Sister. By the time I'm done with you, you'll be sinning so hard for me, you'll be calling me god." 🥰🤭

I didn't think this book could top the first, but I was pleasantly surprised! The author has a talent for pulling you in from the start, and you won't want to put it down. Everything was great from start to finish, with a fantastic plot and pace. I also loved the character growth throughout, and of course, the spicy scenes! 😉🤭 I can't wait for what this author has in store for this series!

[Lanna Wright · Rating 5 out of 5]

ARC reader.

I could not put it down! Of Sinful Secrets mixes a compelling story with spicy scenes that had me gasping. Wonderfully written characters. Chasity’s motivations and ultimate revelations had me cheering and tearing up. Asmodeous takes “touch her and you’ll die” to a new level. The buildup was as sweet for me as it was for the characters.

Warning: Trust the trigger warnings here, it is not a gentle portrayal of the church. If you can handle the heavy themes, you won’t regret it.

[Alesa Herpy · Rating 5 out of 5]

This book put me on my knees!!!(No pun intended). A Nun and a Demon of Lust absolutely blew my mind. The spice is through the roof, the touch her die, the teasing and demonic play is without a doubt jaw dropping. Killian did such an amazing job with the first book and this one I will definitely be adding a bookshelf trophy for this book and would definitely read it again and again.