Catalyst

The Savior Complex #1

by Erin Mersey

The world will never forgive me for loving a villain.

Everyone remembers Sulien Seo as a terrorist, but I know he was a hero. Unfortunately, I'm the only person who still believes in him. And now that I’m nineteen weeks pregnant with his son, even my own family can’t stand me. That’s why they cut me off, leaving me to fend for myself as I prepare for my sophomore year of college.

With nowhere else to turn, I’m forced to move in with Sulien’s old Jace and Kane.

Living with them should be dangerous. They’re actual villains, even if they’re not particularly notorious. But somehow, the two of them make me feel safer than I've ever felt before.

I should be smart about this. If I work hard and prove my loyalty, I know I can claw my way back into my family’s good graces.

But how am I supposed to walk away from the only people who’ve ever accepted me for who I am?



Catalyst is the first book of the Savior Complex series. While Origins is not required to enjoy the book, it'll help you understand the world and introduce you to Sulien Seo. Catalyst takes place a few months after the showcase in the prequel. Catalyst features an MMF couple and has light MM content as well as MF and group scenes. Readerdiscretion is advised as there are strong themes. A full content warning can be found within the first few pages of the book.

Genres: Dark Romance

192 pages, Kindle Edition

Published March 13, 2025

About the author

Teacher by day, degenerate by night. Erin Mersey loves to write kinky, bisexual, polyamorous (why choose, reverse harem… etc.) romance novels with darker themes, diverse characters, and heart-wrenching plot twists.

When she is not writing, Erin spends her time playing video games, reading books, and hanging out with her family.

Reviews

[Lola Kilgus · Rating 5 out of 5]

This was a novella following Origins! If you haven’t read Origins please read that first as it has ALOT of information you will need for this book!

This is a book about super heroes and villains but I promise it’s not your everyday story! Callie has lost the one she loved.. or so she thinks.. When she comes knocking on Kane and Jaces door looking for a place after her parents kicked her out for not wanting to comply with her father, things definitely take a turn! Shadow daddy Kane has my freaking heart!! But the way Jace isn’t afraid to speak his mind about anything!! I love that Calista challenged him in his brain and made him want to do better for the family.

I was waiting WAITING on this certain someone to make an appearance and OMG!!!!! Why did it have to end that way I need the next book NOW!!!

“The love I feel for you is the disgusting, cloying, all-consuming love. The type that makes you warp your goals and ambitions just to better suit what the other person needs.”

[Spoiled Princess · Rating 5 out of 5]

loved this book can't wait for the to be continued 🥲

[Jesslynxreay · Rating 5 out of 5]

Loved this. Origins, the prequel, was amazing so I knew right away that I would love Catalyst too! I also love the author’s writing style so that helps (plus, some great spicy scenes). In this book, you go through the emotions of the FMC, feeling her grief, even made me tear up. In this book we get close to the two roommates from origins and we watch their love for one another grow in the sweetest ways. We also get introduced to Sulien’s father who I really like, and we find out that things are not always as they seem. Now, I highly recommend you read Origins first, if you don’t, the ending will be so shocking haha. But my happy heart was waiting for that moment the whole time! Now that the book is done, I’m dying for the next one. I have to know what happens next!

[Bex G-C · Rating 4 out of 5]

ARC review

I really enjoyed this, love the world Erin has built with heroes and villains. She does not shy away from exploring grief and the difficulties of pregnancy.
I love Sulien’s dad showing us the world is in shades of grey and I adore the found family in this book.
The ending has definitely left me wanting more!
I did feel that the pacing changed towards the end getting a little rushed and then a great leap into the epilogue with lots of loose ends but I hope these will be tied up in books to come.
I look forward to seeing where this series is going and would recommend this to anyone who has ever enjoyed superheroes and spice!

[Sammy Rudd · Rating 5 out of 5]

From the get go I was hooked! We left Origins with Sullien alive and Callie standing on a stage. I had thought she had been brainwashed into believing Sullien was a villain the whole time, but no! She and everyone else thought he had died 😭 If I didn't already hate Jack, the first chapter alone would have made me want to rip him to shreds! And the way the rest of her family treated her like the villian?! 😡

But ohmygosh do I love Callie, Jace and Kane!! To see those two get their act together for her was soooo sweet! AND we get Vexxas's side of the story and see how sweet/attentive he is 😍🥰 I couldn't help but to read this in one sitting and I'm dying for the next one already!

[Jenn M · Rating 5 out of 5]

A Brilliant Must Read!

I read Origins and needed this so much that it became a highly anticipated read for me! I gotta say, my heart broke so many times for Callie that it is still bruised. Callie loved Sulien so much and now she is without him, but is carrying his son. She fights her way to a good place with Jace and Kane, only to end up in a bad situation once again. But that ending! OMG I need the next book now! How could you leave me that way?


Loved, loved, loved this read! I want and need more of these books and this author has easily become a 1 click author for me!

[Sara · Rating 4 out of 5]

I am so invested in this series! I'm loving the superhero/villain, things aren't always as they seem vibes! I adore Callie, Jace and Kane and am loving the growth of these characters. After reading Origins, (the prequel, highly recommend reading first), and the epilogue, we have an idea of what's to come next but I feel like there's gonna be some definite plot twists!

[Kenzie · Rating 4 out of 5]

you know what… hell yeah! this isn’t the type of book i would typically pick up but i still had a great time. it was easy to read and flow through and the storyline really was pretty decent. the characters were silly at times but i found them to still be enjoyable and fun. loved it honestly

[Nora Ellen (Nbbookery) · Rating 4 out of 5]

The world knows Sulien as a deceased villain, but Callie knows himself as the love of her life and her unborn baby's father. Faced with an awful decision, Callie leaves her superhero family's home and seeks refuge with her last hopes: Jace and Kane, Sulien's best friend and former roommates. The boys are shocked at first to see Callie, but quickly gets over their surprise when they learn her baby inherited Sulien's pyromantic power and is burning Callie up from the inside. With her two new roommates-with-benefits and an unlikely ally on her side, Callie is facing the world one day at a time. Her plan is flawed, and she finds herself at the mercy of others with a daunting challenge on the horizon.

This book right here. What?! That ending! I cannot. Callie is honestly such a good character. Despite learning about her life in the prequel, Origins, this story really shows her strength. She's not only fighting her family, she's fighting for her freedom, all while teetering on the brink of a medical meltdown. She brings out the good in others, and Jace and Kane are no exception. They are willing to change everything they have to accommodate Callie, and give her as much as they possibly can. I loved how united they became and the strength of their bond. Not only were they willing to step into the gaping hole Sulien left, but they absolutrly stand up tall despite the pressure and odds. However, that ending was just plain mean, and I will be counting down the days until the next one comes out because I need answers so badly

[Screams & Reviews · Rating 5 out of 5]

This book brought back all the feelings that I loved so much about book #1 origins. Which btw I read again 😝 before this one. Even tho I spoke to Erin before I read the book and she said I didn't need to reread it. 🤭 But I enjoyed it that much I needed a refresher.

Anyways!!!!! Yes yes and more yes but uh!!!! I don't want to say it cause I am so upset! Sulien just why... Omg why Erin! If you are coming out with a new book connected to this one. It needs to get out like yesterday! The beginning & the end. You got me girl and it wasn't even April Fools when I read this one.

Cane & Jane are delicious tho! You have Callie which in the first book falls for Sulien. But this book. She is with cane & Jane. Why? You ask.... You need to read the book but the 3 of them. My feelings are towards Jace at this point and I feel cane is taking this too far and I have a feeling it is going to BLOW UP IN HIS FACE. Why I don't know but just a feeling. Is it cute the way he is with callie but boy.... DON'T TOUCH Sulien THINGS! Remember he told you that in the first book. Let's just say Cane doesn't listen. Uh boys!!!

Plus the spicy in this book will have you kicking your toes.

I just love the villains to superheroes in this book and need more, more, more!!!!! I hope this series never ends cause I think it might break me.

Erin you have done it again and all your books are like a delicious red wine I need to get drunk off of. If you haven't read anything by this author. YOU ARE MISSING OUT.

5/5 📚🌟

~Screams & Reviews 🖤💋🫶🏼📚

[Dolores Evans · Rating 5 out of 5]

Catalyst ⭐️⭐️⭐️⭐️⭐️
Girl 😍🔥💯🥵 Release Day is 03/13/25!!!!

My Review 👇🏻
Catalyst is the first book in The Savior Complex series, coming in right after Origins. In this book you get to watch a bond like no other form between Callie, Jace and last but not least Daddy Kane 🥵 obviously I don't pick favorite but I'd love to hear his lines in this book, in person, just sayin. You get to witness as Callie battles grieving, a high-risk pregnancy, and the expectations of her parents. It's filled with twists and turns, a lot of emotions, a bound forming, family drama, and delicious spice. In a book where the Villains may not be the worst people lurking around, but maybe it's the people you call Hero's every day. In my opinion, it is best to read the novella Origins before beginning, but it is also not completely necessary, I just like the finer details. Get ready for a wild cliffhanger, but fear not Erin Mersey is already working on book #2 in this wild Rollercoaster ride!

[Brita Mackay · Rating 4 out of 5]

I knew that the world was never going to forgive me for loving a villain.

All anyone was going to remember about Sulien Seo was that he was a terrorist, but she knew that he was actually a hero. Sadly, she's the only person who actually still believes in him. Now, she's on her own, her own family can't stand her, and making it even harder, she's nineteen weeks pregnant weeks pregnant with Sulien's son. It's the whole reason her family cut her off, leaving her to support herself and figure her life out for herself and making life even harder. She's in her sophomore year of college.

She knew that she had no other choice. She had nowhere else to turn. With nowhere else to turn, she is forced to move in with Sulien's old friends, Jace and Kane.

She knew that living with them should be dangerous. After all, they were actually villains, even if they were not villains of the notorious kind. But in living with them, she finds that she feels safer than she has ever felt in the past.

She knew that she had to be smart about all of this. She knew that she was going to have to work hard, prove her loyalty, and take care of her baby if she wanted to survive what was heading her way. And if she was lucky, she knew that she could climb her way back into her own family, and maybe if she was lucky, they would even accept her baby, despite who his father was.

Did she really want that, though? How could she walk away from Jace and Kane? They were the only ones who had accepted her and her baby, and more than that, they had accepted her for who she was and even her past.

Welcome to the Savior Complex Series. Catalyst is the first book in this new series. While Origins may not be needed to enjoy Catalyst, it will, in fact, help you understand the world better, introduce you to Sulien Seo and other characters. Catalyst will take place a few months after Origins and features an MMF couple, and it does have light MM content and MF and group scenes. Reader discretion is advised as there are some strong themes. Full content warnings can be found within the first few pages of the book.

I actually think, having read Origins after I read Catalyst that reversing the reading order is actually a much more informative read. Origins introduces you to characters that you will meet again in Catalyst, but more than that, it will help you better understand the world and what is going on around the characters. It actually has a lot of information in it.

In this world, hero and villain are nothing more than just words. They really mean nothing.

Catalyst is the story of a hero and villains and the world that revolves around it. The best way I can describe it is Marvel Comics meets The Boys mixed in with romance, and you can't forget about all the family drama.

This was one of the first books that took me a few chapters to get into, but once the book got going and I got into it, I loved it, and I couldn't stop reading. I, in fact, couldn't stop reading, and it only took me like a day and a half to read, so I think I must have really been enjoying it. Honestly, I usually bounce between books a bit, depending on my mood. This book, though, I just couldn't stop reading, and I didn't bounce, so that says a lot.

It is a little typical in terms of a romance. Everyone falls in love very quickly (I think in like two or three weeks), but I am used to that with romances. I loved the plot and found it a bit different and unique. I am looking forward to the next book and can't wait to see what happens next. It really is a great book, even if it is a bit chopy at first. It is a why-choose, pregnant mom, and the characters all just want to do and be better. It's a highly recommend.

I do wish that there had been more of Jace and Kane's relationship. Maybe we will get more of that in the following books. Fingers crossed.

[Athena · Rating 5 out of 5]

I LOVED it! Its a book you can really get into, you stay involved in the story line, hello I shed a tear and I laughed you get the idea! Worth the read, even if you dont like sharing give it a try! I also really dig the superhero/villian theme that is done in what i would consider more conventional with them actually having superpowers! its like Skyhigh (that old movie) meets Spice 😍 Im here for the rollercoaster even tho yes I lobbed my phone at the cliffy. Im a hardcore HEA lover so im chomping for more. NOW If you havent read Origins the PREQUEL novel stop here in case of spoilers lol
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Despite reading origins and thus knowing Sul was alive (spoiler lol) i cried while she was grieving. I was moved and there with her which i always love a good story that draws me in AND keeps me there. The characters are well developed and i appreciate their depth and growth even just from origins to catalyst. I have to say i h@ted her parents from origins and i really really hate em now but gosh if it isnt relatable in a way which probably means i need therapy 🤣 AND DARNIT im mad she "ended up" with the titatiumtw@twaffle but fingers crossed for the best R€v€ng€ 😈💀 in reader history (after molly weasly getting bellatrix lestrange). I adore Suls dad he is precious and I hope we see more of him! RH is one of my top 5 tropes, the group scenes are well done and i appreciate that they are seemingly realistic, 🩸 control (not the same as play imo) and shadows aside lol.

Origins and Catalyst now have a Perma spot in my ever changing library! And im ready for more sunshine!

[Rochelle · Rating 3 out of 5]

So I received this book as an arc. I had a basic idea going in but had no clue about what was happening.

It’s a story of hero and villains and the world revolves around it. Think Marvel Comics and The Boys mixed in with romance and family drama.

Once the book was going I started to enjoy it - I did basically gobble it up on two days, so I must have become obsessed fast with it.

The writing is a little jerky in the start but it does get going super well as it continues on. I did feel like everyone fell in love way too fast (two weeks?) but overall this is a very good story, I enjoyed the plot and I can’t wait for the next book! It’s definitely a book I recommend if you like why choose with a mix of a pregnant mom and characters that just want to do better, to BE better. I definitely recommend!

I absolutely love Jace and Kane. I need more of their relationship also. I wish there had been more!

Note - I didn’t know about Origins the prequel which might have helped me understand things better. Even so, once you get going the story itself isn’t hard to follow but it would have most likely been better had I read that first! Now I’m gonna go read that so I can understand this world the author created better.

[Diana Martins · Rating 5 out of 5]

Hero and villain are just words.

The characters are wonderful, the emotions are sweet, and it's wonderfully steamy.
The main characters are young adults and amazing – so engaging, with their hearts in the right place.
Most of the remaining characters can pack their bags!
But it’s also heartbreaking. I felt a wide range of emotions, with indignation rising to the surface.
It’s set in a kind of dystopian world, where there are only two types of people: heroes and villains.
This book makes you think: What makes someone a villain or a hero? And more importantly, which of these is the better of the two?
It’s a "why choose" (MFM) with light MM. Hopefully, in the next one, there will be more action in that area. But there’s no shortage of super-hot situations. It’s a fast-burn, super-steamy read, with lots of sweet kinks.
The CW (Content Warnings) are important, as there are potential triggers. It’s a fantasy world, but deals with real issues.
I have to warn you about the cliffhanger. It was... WOW! One moment you’re like “NO!”, the next “What? OK, I get why, but WHY?” and then the cherry on top: “WTH?”.
To be continued...

[Riana Turner · Rating 4 out of 5]

Catalyst Review

**Please read the novella Origins before jumping into Catalyst. Origins will help you make sense of what is going on!**

Well done Erin! I enjoyed this book, but leaving us on that cliffhanger at the end was not okay!

Callie is grieving after loosing her boyfriend, who has been kicked out of her hero parent’s house. She has no where to go so she goes to her boyfriend’s place to see if his best friends will let her stay her them. This is where Kane and Jace learn that Callie is pregnant.

Callie has both Jace and Kane wanting to better themselves for her and the baby. With some twists and turns, Callie ends up having to comply with her dad’s request to save her and her babies life. Both Jace and Kane say they will come back for her and that’s what gets her to go and keeps her going.

The major jaw dropping twist comes right at the end, someone comes back into her life she wasn’t expecting to see.

Cannot wait for book 2 in this series!

[Charlene Alana Henderson · Rating 5 out of 5]

This is my first time reading a book by Erin mersey and let me tell you it won't be my last, I fucking loved this first book in the savior complex series. I just couldn't get enough of their story. I ate this baby up, never putting it down for a second, it has me on an emotional rollercoaster ride with twists and turns. It's action packed and breaches hard subjects like grief, high risk pregnancy and trying to cope with your parents high expectations. I instantly fell in love with Callie, Jace and kane. Did someone say daddy!! They all formed bonds that was truly amazing to see. The storyline and plot was wonderfully written and held my interest all the way through. Heros and villains of the world. I can't wait to read the next book by Erin mersey. But damn that ending talk about a cliffhanger!! Highly recommend!!

[Isabelle · Rating 4 out of 5]

The whole idea around Villains and Heroes I loved, it felt different and interesting and definitely had me wanting to read more about it.
I like that the characters are flawed, they aren't perfect and some aren't very nice people to start with but you see their characters develop.
So whilst I enjoyed the plot and the characters a lot, I did struggle more with it being fast paced. When grief is a strong theme in this, I wanted it to feel more raw and gritty and take maybe a bit more time to focus on that. It is a short book, and it also moved quickly through the timeline with parts skimmed over which meant I didn't feel as connected as I would have liked with them.
But I do really love the relationships, the characters and the world created so will pick up the next in the series to see how it develops.

[Carly Fay · Rating 5 out of 5]

Amazing book! If you’ve read Origins, the prequel, you’ll know the biggest spoiler but that doesn’t stop you anticipating when it’ll unravel - so I highly recommend reading it to set the scene! I loved the way the characters grew, & how the FMC’s relationship with the two roommates from Origins developed had me in a chokehold. The spicy scenes were spicing, & the villains & heroes switched roles! As we meet more characters, things are not all what they seem to be, & the FMC struggles to come to terms with what she learns. I absolutely loved the relationship between the FMC & MMC’s, even if the start was a bit rocky to say the least! On the edge of my seat waiting for the next book - I NEED to know what happens next!

[sourpatchsue · Rating 5 out of 5]

Wow this was amazing. I was hooked from the first page. The characters were amazing. The plot was perfection. The spice was perfectly placed and helped the story flow. You know how we all fall for the villain in romances in this you really should fall in love with the villains. Ending on the perfect cliffhanger making it impossible not to want the entire series. I felt all the emotions with this book and I am so ready for the next book. I recommend this book so much. I really wish I didn’t have to sleep or do the cleaning I just wanted to hide in my blanket fort with no distractions. This book is not my normal style but it’s definitely top tier. I would even recommend to my husband who isn’t much of a reader and he would love this series too.

[Sarah Herridge · Rating 4 out of 5]

If you haven’t read Origins I strongly suggest you read it before this book as it will fill in loads of info you will need to get the full enjoyment of this book.
After being kicked out of her parents house Callie goes to the only place she thinks will accept her to her lost loves room mates and friends.
I love the way this book builds the relationships between Callie, Kane and Jase.Callie also sees that not all villains are actually as bad as they are made out to be.
The book ends on a gripping cliffhanger that makes me way the next book NOW!
Is the hero and villains would actually black and white?
Are the villains really the bad guys?
I’ll let you come to your own conclusions on that.

[Ashley Fields · Rating 5 out of 5]

Ahhh, I loved this start to the Savior Complex series!

I was really intrigued when I read Origins (the prequel novella) because superhero smut is such a unique idea that I really haven't seen done before.

Catalyst continues to dive into the whole idea of villains vs heroes and what exactly makes someone a villain. It's really fascinating and I love the world that Erin is building.

The characters were great - Jace and Kane do such a good job trying to take care of Callie, and show her how much they love her. Found family is one of my favorite tropes. 😍 Sulien's dad, Shin, was a great addition to the book as well and I love how he basically adopted Callie & helped open her mind to what her family is really like.

And that EPILOGUE. 😳 I'm so excited to see where the next book goes.

[Haley Breeden · Rating 5 out of 5]

EXCEPTIONAL! PHENOMENAL! BRILLIANT!

This book was SO GOOD!

From. The moment I started to the moment I finished, it didn't let up. I read this in one sitting, and I loved every single second of it.

Miss ma'am had no business making Kane and Jace as freaky as they were....but dang was it hot. And the shower scene? I went from "oh?" To "ooooooh" real fast.🥵😂....But also i love both of their character developments as people. How they grew and how they loved Callie as just a person💓

THE ENDING!!!!? That one had me dropping my jaw. I NEED TO KNOW WHAT HAPPENS. How am I supposed to wait!? HOOOOW!?

[Ashley De Dios · Rating 5 out of 5]

I read the prequel Origins, unsure if the superhero trope was going to be for me or not and I flew through it so quick I was hooked! I was so stoked for the next book in the series and Catalyst delivered!!! This book was such a rollercoaster of emotions, I just about d!ed. Callie has gone through it all and then some and her grieving Sulien still has my heart bleeding. But the family shes found in Jace and Kane is amazing, Im obsessed with their little trio. And holy heck the things Kane can do with his Shadows and Jace with his Hemomancy, woahhhh baby 🥵 the cliffy at the end this book has me on the edge of my seat waiting for thr next installment, I cant wait! If you think it sounds even a little bit interesting just read it, youre doing yourself a favor and you won't regret it!

[Smuttybookoholic · Rating 4 out of 5]

I honestly didn’t know what to expect when I started reading this, but I enjoyed it very much! This was the first book I read where the fmc was pregnant the whole time and there was a pregnancy kink! I’m not mad about it! I love the dynamic between Jace, Kane, and Callie. The last chapter threw me got a loop and especially that cliffhanger, I need the next book asap! If you’re looking for a book with hero’s and villains, but in this case not all villains are that bad, then I 5/5 recommend reading!

[Tabatha Slagle · Rating 5 out of 5]

I'll start out by saying this story was PHENOMENAL! The ending though, sent me straight to her messages because what in the what. The last line of the book was definitely my favorite.

I loved Origins and this was a continuation of that story. We got more of Calista, Jace, and Kane. We get to see the development of their relationships with each other as they tackle the loss of their best friend/love. The found family vibes in this book are the absolute best. I cannot wait for more of this story because I know that I will just gobble it up.

[Jenn · Rating 5 out of 5]

Phenomenal Story!!

This book! Again, if you are looking for a book where superhero’s and villains are involved, then look no further! This book had me on the edge of my seat. The twists and turns help make this book everything that it is! The character development is absolutely fantastic and I love how things developed. Now, can we talk about the cliff hanger (if you know, you know)?
Erin, this book is everything I did’t know I needed until I started reading it! I can’t wait to see what happens next!

[Claire Carruthers · Rating 5 out of 5]

4.5 stars rounded up to 5 stars

And the sequel....just as blooming good as the first!
I absolutely loved the changes in dynamics between the main male characters- Kane and Jace, and the fmc- Callie compared to the first novel- Origins.
You really start to vote for the three of them, through all the challenges thrown their way and what is upcoming for them.
Until that ending - what a cliff-hanger!! I am shook and cannot wait for the next in the series.

My thanks to Erin Mersey for the opportunity to read Catalyst as part of her permanent arc team. All comments are my own.

[Jessi · Rating 5 out of 5]

⭐️⭐️⭐️⭐️⭐️
🌶️🌶️🌶️🌶️

Oh heck yeah! That epilogue! Ooooooo.

I am a HUGE fan of Erin’s. And I always will be. This book was a pleasure to read! I have so many questions and I am so excited to read what’s coming next.
Callie is a force to be reckoned with and I can’t wait to see her shine. Especially now that I’ve read that ending. 👀👀
Jace and Kane are fools in love and it’s perfect and wholesome. They want to do anything and everything for their girl. Even if it means they’d suffer.

So good.

This book has MMF, mentions of d3ath, pregnancy, found family and so much more.

[Jessie · Rating 5 out of 5]

I couldn’t wait to get my hands on this book after reading Origins. The story of Callie, Sulien, Kane and Jace will rip your heart out, in the best way. The spice is off the charts hot. Callie comes from a family of heroes, but they certainly don’t come across that way based on how they treat her. This book further flips what we know about heroes and villains and how a label doesn’t actually define a person.