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Demon Bound #4

Unleashing Mayhem

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Matteo’s been running scared for so long he’s forgotten what it’s like to feel safe. Or maybe he never knew in the first place. Raised by a cruel man, tormented by an even crueler one, and recently rescued by a demon, Matty’s still jumping at shadows around every corner. When he sees a familiar face from the past and realizes his ghosts really have come back to haunt him, Matty does the only reasonable thing he can think of.

He summons someone even worse.

Nightmare is a solitary demon by nature. He’s never needed a companion or a lover or a friend, and he’s never minded being feared by others of his kind. But one taste of Matteo’s sweet, terrified soul and Nightmare needs more. When he’s finally summoned to Matteo’s side, Nightmare finds himself exactly where he wants to be. Now it’s only a matter of patience, seduction, and convincing his little human that one contract isn’t enough.

What they really need is an eternity.

Unleashing Mayhem is a heated MM paranormal romance with a HEA and no cliffhanger. It contains a sweet human afraid of everyone but the monster at his side, a demon so possessive even other demons run scared, a found family made of mobsters and monsters, and a summoning gone right (for once). While each book focuses on a different couple, the series is best enjoyed in order.

246 pages, Kindle Edition

First published July 17, 2025

266 people are currently reading
625 people want to read

About the author

Grae Bryan

23 books1,188 followers
Grae Bryan has been reading romance since she was far too young to know any better. Her love for love stories spans all genres, and while her current series is of the paranormal variety, she knows she’ll be exploring other worlds further down the line.

She lives in Arizona with her husband, who graciously shares space with all the imaginary men in her head. When not writing, she can generally be found reading more than is healthy, walking her monster-dog, or cuddling her demon-cat. She loves anything and everything gothic, strange, lovely, or cozy.

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5 stars
1,100 (47%)
4 stars
770 (33%)
3 stars
355 (15%)
2 stars
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Displaying 1 - 30 of 246 reviews
Profile Image for ~✡~Dαni(ela) ♥ ♂♂ love & semicolons~✡~.
3,610 reviews1,146 followers
July 19, 2025
~4.25~

Hands down my favorite of the four books in the Demon Bound series, this is the squishy, sad, violent demon/human romance I didn't know I needed. One of those adjectives is not like the other, but this was a truly comforting (squishy!) story despite the horrors Matty survived.

Matty has always been scared. Sold by his cunt of a mother (I wish the demons had killed her while they were at it), tortured by his stepfather's henchmen (one in particular), Matty was raised without light. He hides in oversized hoodies and blanket burritos. The only time he's not terrified is when he sees Nightmare in his dreams.

Nightmare feeds on people's fears, their most gruesome thoughts. He doesn't talk much and gets lost in shadows. He's been alone for centuries. Until Matty calls to him.

Matty summons his protector on purpose, and Nightmare is everything Matty wanted in a mate and more. Plus, Nightmare's shadows adore Matty, so one is always wrapped around him like a blanket.

Sooo squishy!

Despite the darkness lurking in corners, Unleashing Mayhem is all about holding hands, eating lemon squares, watching the ocean, and cuddling up. It's a mayhem of gooey and romantic, with loads of humor and the cutest conversations.

The revenge porn isn't half bad either. Evil people getting their comeuppance is quite satisfying.

Matty and Night are ridiculously adorable together. Matty's inner sex demon is unleashed, so it gets hot & wild. Grab a fan.

All the demons and their mates come together at the end. It's a big family reunion, despite the possessiveness, hissing, growling, and jealously.

DEMONS, amirite?

P.S. One minor source of contention: The cover features Nightmare as a human (because no way is that Matty). Night is described as tall, slender, tats, pale skin ... all good, except in Nightmare's human form, "his white hair turns jet black." Um, yeah, I'm not seeing any jet black hair no matter how much I squint.
Profile Image for Dani.
1,707 reviews337 followers
July 17, 2025
Favourite couple of the series!

I loved how Matty and Nightmare called each other Scary and Sweet 😍

Nightmare being all in immediately was so fun and I was so glad that they got the bonding done and that it wasn't the main conflict.

Matty made me laugh at how into horror he was because he does come across as a marshmallow, but I really loved his feisty and vicious sides!

Kinda sad to be saying goodbye to the demons, but I'm really intrigued by the ABO book that's coming, and the new paranormal series too.

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HRCYED2: Spooky Creatures
Profile Image for taylor :).
268 reviews63 followers
August 14, 2025
i really liked this but i think it was missing something?? although i don’t know what that could be. i think i just really hyped it up in my head so i was expecting just a little more? idk but i still liked it. book 1 was my favorite overall though
Profile Image for martina (the life of a chaotic reader).
807 reviews441 followers
July 17, 2025
3.5

okay i don’t know what happened, and im probably just in a weird mood.
i was so excited for this but it feel kind of flat?
and i don’t even know why, because it has all the right ingredients, but it’s not having the desired effect on me.
it has all the demonic possessiveness i love, so i don’t know why im not squealing like a rabid squirrel, but im simply not.

i do feel like it’s me, not the book
Profile Image for Cadiva.
4,013 reviews447 followers
July 22, 2025
What a fantastic book

Who'd have thought that the most terrifying demon in the Void would turn out to be a squishy marshmallow for his mate!

I absolutely adored this story, I'd been holding out hope that Matty would get his HEA, and he does in some style.

Nightmare is the perfect demon for him, he's been protecting the young man in his dreams for quite a while when Matty finally uses the summoning page to call him out.

His appearance isn't frightening for Matty, instead he feels safe with his tale, pale, antler-topped demon guardian, especially when he realises that Scary is capable of ending his fears for ever by taking out the man who's causing them.

One thing mind, the beautiful cover clearly depicts Nightmare, except his white hair in demon form turns JET BLACK like a mirror image in his human one.

It's a minor niggle but when all the covers have been outstanding and reflected the demon half of the relationship so well, I was surprised that this one got the fine details completely opposite.

With a full complement of guest appearances, this book neatly finishes off this series on a huge high note and I am very much looking forward to seeing where this universe goes next with Grae's imagination.

Probably my favourite one of what's been an outstanding collection of urban fantasy/paranormal narratives.
Profile Image for Kit (kit.reads.romance).
164 reviews21 followers
August 15, 2025
Fellow monster fuckers, pay attention! He is big. He is spindly. He has a weird peen, antlers and a skull face. His name is Nightmare and he is here to crush your enemies and claim your soul! Daddy Scary can get it, people.

(No actual Daddy kink present for anyone wondering).

Is this my new favourite Grae Bryan book? Can this actually beat Johann for top spot? The fact I'm even asking this question should tell you how much I LOVE this book. Matty is my cute, precious, slightly strange little bean who I want to burrito blanket so badly and save from all the horrible things he had to go through in his former life. He is innocent and sweet and bloodthirsty and vicious all at once and I adore him.

Nightmare is the big, scary, soft only for you protector that Matty needs! Nightmare is all in from day one and will do anything to keep his precious Matty happy and safe. Nightmare is also possessive, a bit mean to anyone who isn't Matty, and totally inhuman in the way his thinks and feels. I adore a properly monstrous character!

Add in some adorable soot sprites shadows which have their own sentience and love on Matty too (along with crime scene clean up, very handy); cameos including my beloved Chaos who has some of the best lines in the whole book; and plenty of delicious and imaginative spice, and we have ourselves one fantastic book!

Do not miss the series if you enjoy paranormal romance, found and bio family thriving against all odds, slightly ridiculous demons, or a great mixture of humour and hurt/comfort.

I received an advance review copy for free, and I am leaving this review voluntarily.
Profile Image for Elizabeth.
479 reviews100 followers
July 20, 2025
"Sweet" and "Scary" was adorable. I had high expectations for this book and Grae didn't disappoint me.
Profile Image for Mimi.
718 reviews158 followers
July 18, 2025
I knew this was going to be good, even great, but in no way did I expect it to be this flawless?! trust Grae Bryan to release her best book yet AND deliver everything and more with Matteo and Nightmare 🤝🥺
Profile Image for Dan.
1,748 reviews49 followers
July 27, 2025
This was so good. Matty is so sweet and wounded and Nightmare is exactly what he needs to make everything right. And he does so in an appealing, exciting way. I loved it.
Profile Image for JonathanSamuelReads.
260 reviews35 followers
September 3, 2025
‘And when Matteo finally blossomed into who he should have been all along—who he might have been if cruel men hadn’t taken him in hand… A sweet, tender being with teeth as sharp as jagged knives. Then Nightmare would devour him whole.’

I love this so much! Nightmare was the perfect mate!
Profile Image for Rachel Emily.
4,482 reviews382 followers
October 17, 2025
Well this is hands down my favorite book in the series. I just adored Matty and his Nightmare. I'd say that this might be the darkest book of the series as well, but there is such a softness and sweetness to Matty as he heals from his past and finds love with the scariest demon of the bunch, that it never gets *too* dark, if that makes sense.

I loved getting to see so many of the previous couples in this one, and everyone working together to help Matty.

Michael, as always, is an excellent narrator. I loved his voice for Nightmare, I don't think I hear this character voice from him very often if ever.

If you're a fan of hurt/comfort, possessive mates, scary demon/sweet and soft human pairing, and overall demonic shenanigans, then you will love this book. I have really enjoyed the whole series and if this is the last one?? (not sure if it is or not) then it really went out on the highest note for me.

I received an audio copy to review, my thoughts are my own.
Profile Image for Mir.
1,135 reviews67 followers
August 3, 2025
Empty calories. It’s fun and cute but ultimately empty. I liked it a lot more than books 2 & 3. I wish it was more though, because there doesn’t seem to be a lot of great MM fated mates books out there.
Profile Image for Luz Rivas.
520 reviews28 followers
July 29, 2025
I’ve been waiting for this book since the start of the series. I needed to see little sweet Matty get his happy ending, and honestly, from book one it was clear that Nightmare was going to be his destined partner. What I didn’t expect was for dear little Matty to be this naughty 🤣🤣

It’s so fitting (and a little ironic) that the scariest-looking demon ends up being the perfect match for Matty, who until now has lived terrified of his own shadow. But the truth is, Matty knows real monsters aren’t demons who feed off fear, they’re cruel humans. And Nightmare? He may be terrifying, but he protects Matty with everything he’s got, and that makes him the safest place in the world.

I was very happy with how Matty took revenge on the person who tormented him his whole life, and I loved that Nightmare helped him achieve it. I totally understand why Kai isn’t a fan of Nightmare’s methods, after all, he’s a warrior who believes in fair fights, but some enemies are so cruel and merciless, especially toward those who can’t defend themselves, that they deserve a taste of their own medicine.

For a moment, I thought the relationship between Sasha and Matty would suffer because Kai and Nightmare don’t get along, but I was relieved to see they were both willing to do whatever it took to make their mates happy. Even if that meant tolerating each other 🤣

Now that the series is finished, I make my ranking of it:

Book 1: Wreaking Havoc – ★★★★☆
Book 2: Inviting Bedlam – ★★★★★
Book 3: Calling Chaos – ★★★☆☆
Book 4: Unleashing Mayhem – ★★★★★

This was the ending I wanted for Matty, and I couldn’t be happier with how it turned out. But is a bittersweet ending since I didn’t want the series to end.

But I hope I would see more of these characters when/if the author decides to make a series of fae companions after Benny got his own little novella. For real, Seth also deserves his forever boyfriend. Better if said boyfriend is stupidly handsome 😅😍🙂‍↕️
Profile Image for Arwen Reads Books.
139 reviews9 followers
August 16, 2025
This, right here, is my favorite book of the year.

I've been drooling after this book for months and I wasn't disappointed: it was perfect. Everything I wanted, really: violence, scary mighty demons who are secretly so so soft to their mates and, of course, so much fluff.

The book was NOTHING like I thought it'd be, and it made it even better. It surprised me in the best ways possible and, honestly, I might be a little obsessed. I just love Nightmare and Matty and want so. Much. More.

Matty reminded me of Jay, in a sense. A cute and demanding little blood thirsty fluff ball. I'm sure they'd get along SO well. Nightmare was everything I wanted him to be: selfish and violent, but also incredibly collected... ugh, he was the hottest. Everything was very fast-paced but honestly, I didn't even mind it. In fact I was totally hoping it would be.

Grae Bryan can do no wrong. I can't wait to see what's next on her PNR journey!

I recieved a free copy of this book and this is my honest review
Profile Image for ❀ Jess ( Semi hiatus ).
878 reviews99 followers
July 17, 2025
Update: *happy sigh* this pairing was so good. Nightmare really reminded me of Wyn and I'll always love monsters who are actually monstrous and are soft ONLY for their person. And the fact that Matty loved everything about him from the beginning was great, and how he's normally scared and quiet but is possessive of his monster? I loved it so much! 🥰

I'm not really sure why it wasn't a full 5 stars for me though. Although I really liked these two together I still felt like something was missing..

I think I might've been a little disappointed that Matty didn't express more concern about Nightmare's pain when he asked him about being hurt..Still, I think this might be my favorite pairing out of all the books I have read from this author. 🥰
This entire review has been hidden because of spoilers.
Profile Image for Courtney Bassett.
804 reviews195 followers
January 28, 2026
Soooooo good!

Wow! This might just be my favorite of this series. The hurt/comfort was amazing, and the dynamic between Matty and Nightmare (or “Scary,” lol) was fire. I adored it start to finish, and it’s going straight on my comfort read shelf!
Profile Image for Sandra .
1,989 reviews347 followers
July 28, 2025
Matteo, who hides inside blanket burritos from the monsters of his past, who lives in near constant fear, who has nightmares and is afraid to sleep, get the perfect demon to chase it all away.

Scary is summoned by his Sweet, and I FLOVED this.
Profile Image for Ash.
401 reviews28 followers
August 23, 2025
I liked this one more than the previous 3 and I’m not ashamed to say it 😂

On a completely unrelated note, I still have a deep fondness for shadow daddies. 🙃
Profile Image for Jacquie Stewart.
2,658 reviews74 followers
October 9, 2025
I really enjoyed how much Matty loved his scary demon. For someone so afraid of everything, he didn't blink at Nightmare.
Profile Image for Leigh Gaskill.
847 reviews34 followers
August 27, 2025
I have been dying for Matty’s story since he was rescued in book 1 and it was so worth the wait!

Nightmare is absolutely perfect for Matty, and I love how feral they are for each other. They remind me of Danny & Wyn from Soul Eater, except Matty is a little bit bloodthirsty!

This was perfect. Loved the whole thing. They are my favorite.
Profile Image for 369Pages.
724 reviews35 followers
July 17, 2025
3.5⭐️
The fourth book in the Demon Bound series is here! I was so excited for Nightmare and Matty’s story.

Matty has been staying with his friend and his friend’s demon lover. Hiding out and afraid to go outside, in fear of abusers from his past. When he’s left home alone, he decides to summon a demon protector of his own. He is surprised to find that the terrifying demon he summons is the same demon that’s been protecting him from his horrible nightmares.

You’re going to get:
- Big scary demon / meek human
- Somno 👀 (like, a lot)
- A lot of cameos from MCs in the other books
- Bad guys getting what they deserve
- Big protector vibes
Like most books in the series, this book mainly focuses on the dynamic between the MCs, with a simple B plot to drive the story to a conclusion. I really enjoyed the protectiveness that Nightmare was giving, and his shadow powers were cool. I loved that the theme of sleep was interwoven in many key parts in their relationship (and no I don’t just mean the sexy ones 😂).

That being said, I felt like the flow of this book was a little choppy, and the characters ended up falling a little flat compared to those in other books. Both Nightmare and Matty are very one-note in terms of personality and depth. I liked their chemistry by the end of the book, but it felt a little strange at the beginning.

Overall I still enjoyed reading the book, and I love the universe that it’s set in. Definitely excited to see what this author writes next!
Profile Image for Caitlin.
591 reviews
August 18, 2025
4.5 stars

Ahh this book was such a joy to read.

This series had me so conflicted at times because while I enjoyed book one, it wasn't a favourite of mine... but then I read book two and was obsessed with it. Book three came along and again it was good, but not a favourite... and we're repeating the cycle because I loved this book and feel like I'll be rereading it in the future.

I had no idea how I really felt about Matty or Nightmare as characters before delving into this book. I feel like I was mainly just trying not to get my hopes up too high in case I wasn't as in love with this book as I was with book two.

Buuuut looks like I didn't have to worry at all. I loved both Matty and Nightmare, and reading from both of their perspectives was so enjoyable. I like that Matty still had that little bit of bloodlust running through him and that Nightmare was more than happy to indulge his mate's desires. They fit together so perfectly well, and I really enjoyed how each of our other couples (who doesn't love a found family trope) were all included in this book -- even mentions of those from the Vampire's Mate series!

P.S. I love how everyone else thought Nightmare was hot. That scene where Nix was scolding Ivan for looking at him for too long? Iconic.
361 reviews41 followers
July 23, 2025
Oh, Sweet and Scary. Love the nicknames. Love the insta-claim. Love how the big, scary Nightmare and the adorable, scared but fierce Matty fit so wonderfully together. You wouldn't think sweet and scary would be such a good fit, but man these two just work!

This is a fun, sexy read in a series that is definitely up there for me. These books do have plenty of violence (but it's against really bad men so it's all good!), but the sweetness more than makes up for it. Grae first made a vampire nest and has now created an adorable, if not a teensy bit dysfunctional demon family. I do so hope this author stays in the paranormal and I can't wait to see what's next. With Helio and Benny making an appearance in this (how freakin' cute is Benny!?!?), I definitely wouldn't mind some more fae romance.

Highly recommend, absolutely adored.
Profile Image for Yackie.
627 reviews5 followers
Read
July 24, 2025
Me: “the book I’m reading is so gross”
Lexi: “the Wager?”

No, this book.
Profile Image for Elena Rodríguez.
1,224 reviews491 followers
January 2, 2026
“I’ve met real monsters. Zombies and slashers and killer alliens, those are just pretend”.

El mejor de la saga a mi modo de ver. Nightmare ha completado el ciclo de los cuatro libros. Me ha gustado mucho como de protector se pone con Matteo. Demasiado lindos.

“I will be your jagged pieces, Matteo”.
Profile Image for marteetaa.
21 reviews2 followers
August 11, 2025
no development whatsoever for their relationship? to me it felt like a copycat version of the past book with a grumpier demon and that's it. i actually did not even like matty, something about his story and development made him so detached from the storyline.
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