Dragon Blood Curse

Emperor's Assassin #4

by Kai Butler

The generals that once served Emperor Tallu now pursue us across the continent. We have one chance to save our lives, one hope at a future that we both so desperately want. With new allies and old nemeses, we have to risk our lives to create a world for our love.

Genres: Fantasy, M M Romance, Dragons, Historical, Royalty, Adult, Queer

379 pages, Kindle Edition

Published March 16, 2026

About the author

Kai has been reading and writing romance novels since she was a teenager. She lives in California with her two children and her very supportive husband.

She writes M/M romance with an emphasis on HEAs and all the feels. Her current series are San Amaro Investigations and the Imperial Space Regency Novels. She likes dashing heroes and couples with banter.

Reviews

[Sam *Just the Highlights* · Rating 4 out of 5]

2026: 4.0

[Melanie · Rating 5 out of 5]

exciting, entertaining read

Rating: 4.5🌈

Dragon Blood Curse was an exciting, immersive experience all around, as Butler’s penultimate story brings more mythical characters and magical regions into play with this fantasy action adventure.

Prince Airón and King Tallu have multiple schemes at work and not all are going according to their intended intentions. With their enemies bringing larger powers and armies against them, Airón and Tallu race to find a cure for the deadly curse that affects both brothers. And their own council falls into chaos and loyalties are divided as the enemy attacks.

It’s high politics, subterfuge, magical terrorists, and wars between enemies being waged across their borders and territories, and everything and everyone suffering.

Of course, there’s a prophecy or two, sacrifices that figures mightily in the coming novel, angst and some really great layering of information and people (look to the North) that just ups the stakes here.

No spoilers but this just grabs the reader from start to finish. For me, the relationship between Airón and Tallu is the least compelling element here. So many other great aspects of the series and story to focus on.

Great job. And I love the Spider. Awesome.

Cover by Hannah Latham at oexasart Lettering by Laura at Covers by Aura

Emperor's Assassin (5 book series)
Betrothed to the Emperor #1
Emperor's Wrath #2
Shadow Throne King #3
Dragon Blood Curse #4
Crown of Ash #5 - Oct 26,2026

[Ailyne · Rating 4 out of 5]

Im really going to need my boys to have a HEA because I AM TIRED!

[Rasa || beviltiska_romantike · Rating 5 out of 5]

4.5*
"What I am going to do with you, if you insist on throwing yourself into danger?" Tallu asked.
"Love me half as much as I love you", I said.

[Dalegendaryreader · Rating 4 out of 5]

“I want you. I want a life with you. That is not possible as long as the Imperium survives.”

The generals that once served Emperor Tallu have the Imperium and declared war. Emperor Tallu and Prince Consort Airón have to find new allies at the same time embark on a secret journey to save their lives.

Started reading this during release day because ya girl couldn't wait but I also saw the next book gonna be published this October so I debated whether to binge-read this or savor. I chose savoring the book.

Ngl, the reason why this was not a 5-star book was because of all the travel. I get it, it's a fantasy book and they have to travel but dang, I don't really like the travel aspect in books. Not the book's fault, but it's me.

“Tallu, I cannot save you if I lose you first.”

I love how much more high stakes we are. Every book and in every journey is one step closer to Emperor Tallu and Prince Consort Airón's end goal. I love it sm! The adventure, the way the politics works, it was amazing on how the author wove together the story. You can see there's a way and that everything is a stepping stone.

“It is better when you are with me.”

The romance sprinkled in here was so endearing. We know what are at stakes and yet we can definitely see how fiercely Tallu and Airón loves one another.

I cannot wait for October please.

[SNik · Rating 5 out of 5]

Fourth in series (Emperor’s Assassin), must be read in order. Fantasy. Established couple. Found family. Single POV.

Immediately following book 3, Airón and Tallu remain intent on tearing apart the empire, however they are racing against time as they are pursued by the traitor generals and trying to find a way to end Tallu’s blood curse.

Since Airón and Tallu are solidly in love and committed to each other in all ways, this story hits harder with Airón’s desperation to save Tallu. The journey across the empire still has them deep in political intrigue and trying to survive as they juggle the outward appearance of trying to save the empire while secretly planning its demise. As the story is told from Airón’s POV, it was fun to read as Airón is super capable and a main character to root for, his love for Tallu drives all his actions, and he is admirable and intelligent as well. I thoroughly enjoyed this entry in the series, the group of supportive characters that are loyal, the commitment Airón and Tallu have to each other, and the overarching hope to bring about a better empire.

[Copper · Rating 4 out of 5]

Catching back up with Airón and Tallu as they continue their secret mission for the good of the empire and their own happiness. More court politics and political manoeuvring going on to keep you interested. But also a lot more history on the land and the people of the extended empire.

Seeing everything from Airón gives him a strong voice and I find his thinking can be hit or miss, giving interesting outcomes for both. This also gives Tallu some mystery over his interworking, although at this stage of the story they are both so manly in love that he's mostly thinking of the empire or Airón. I love how the pair have grown together and deeply love each other now.

Also love the pair of dogs Asahi and Sagam I wish we saw more so excited they are getting their own book soon. I find their love story so sweet but tragic, I really hope they can build some happiness.

Looking forward to the next book, the last few chapters here really had me going. I'm interested in how this next installment will play out after the event in this one.

[Mimi]

I think I might be getting tired of this series bc I gobbled up the previous books but am having a hard time with this one.

The plot picks up with immediate action right from where the last book left off and it felt very disconcerting. There was no break to gather my bearings, you’re immediately thrust into all the intrigue. I read the last book only a few months ago, and still felt very lost. I fear that folks who haven’t read the last book immediately before this are going to have a hard time.

It also feels like the romance has taken a complete backseat to the plot. This wouldn’t be as much of a problem if we got other POVs, but bc we only get one MC’s POV, so this epic plot and world building starts feeling very narrow and constricted.

I prefer Hailey Turner’s approach to the Infernal War series than the way this series is evolving. It’s too many books from only one character’s POV for such a epic heavy plot and it’s all feeling very chosen one focused bc of that. Hence why I’m having a really hard time with my rating even tho I really enjoyed the previous books.

[avid reader 1 · Rating 4 out of 5]

4 ¼ Stars

Dragon Blood Curse is a great continuation of the Emperor's Assassin series. I strongly recommend rereading previous books in this series before reading this one.
Tallu and Airón continue to support each other and their goals for the empire's future. There is A LOT of political talk in the first half of the book. It lost my focus at times, but I’m not a big political person, so I guess that’s a “me” thing. Many of the characters will receive the side-eye since I have become suspicious of almost everyone on these pages. The depth of the characters and the worldbuilding in general continue to impress me.
Airón and Tallu are wonderful main characters, and I feel closer to them with each successive book. Even with the single POV, I know Tallu just as well as I know Airón.
I am invested in the lives and HEA of these two and in the outcome of their political partnership.
I look forward to more from this author.

[She Who Shall Remain Nameless · Rating 5 out of 5]

Excellent new addition to the series! I highly recommend rereading the previous book in this series before reading the new releases just to reacquaint yourself with the storyline. I purchased this book directly from the author, which I highly recommend as a way to both support your favorite authors and not spend money with Amazon. This book helps further Airon and Tallu’s quest. There was a bit more political intrigue in the first half of the book than I prefer, but the second half had a bit more action to it. Overall, this is an excellent series which I highly recommend. I can’t wait for book 5 to be released.

[Juniper · Rating 5 out of 5]

This is book 4 in the series, and a gentle note to readers that starting at the beginning is a good idea. This book delivers everything that’s made this series so compelling: immersive, layered world building that blends magic, intrigue, wonder, and genuine peril in a way that never loses its sense of stakes, and absolutely no dull moments (plenty happens, and I’ll leave it at that — the plot deserves to be experienced on its own terms). What anchors it all, though, is Tallu and Airon, whose connection is a real source of strength and depth — for each other and for the story.

*I voluntarily reviewed a complimentary copy of this book

[Hani · Rating 5 out of 5]

I LOVE political intrigue in my fantasy books. This one stands out because they're politicking while ON. THE. MOVE. It was so awesome and exciting. So often, I get blimey one-liners of royal travel. They travel to go to a location to politick. Yet, there's a reason Air Force One travels with a full complement of staff and press: politicking doesn't stop just because you're on the go. Yet, so many writers never cover the politicking that happens on the move. Travel is apparently only for action and violence, or quests and toil.

So I AM SO HAPPY!!!!!!!

[SandyB · Rating 5 out of 5]

What started as a story of court politics and arranged marriage machinations has grown into an epic fantasy with political intrigue, amazing worldbuilding, and high adventure. Picking up right after the last one (read in order!), Airon and Tallu deal with magic gone awry, forces beyond their control (maybe), and traitors big and small. Every character has purpose and is fully developed, every event has ramifications throughout the rest of the book. I savored every bit of it.

[Jewel · Rating 5 out of 5]

I am LOVING this series. Tallu and Airón have been through so much and there is more yet to come. I think I will reread the whole series before book 5 comes out.

This series has so much I love in a fantasy story - magic, intrigue, bratty dragons, even brattier ravens, curses, adventure, quests, loss, and love. *chef's kiss*

[read b00ks · Rating 5 out of 5]

This is possibly my favorite fantasy series. I love Tallu and Airon. Yet again they're faced with nearly impossible obstacles and surrounded by people they can't trust. Just when they've got a handle on it, a new issue pops up. I can't wait to see what happens next.

[Noah Shoshan · Rating 4 out of 5]

4.75/5. Listened on audible. HOLY FUCK! Best novel in the series so far. The first part kinda dragged a little but as soon as it picked up in the middle, it was brilliant. I hope in the next novel we will see a bit more of Sagam and Asahi’s relationship. Now I have to wait until the next book

[Dee · Rating 4 out of 5]

This was my least favorite of the series thus far but was still a well written story. I think there was significantly less relationship building and lovin’ on each other between the MCs, so that’s probably where most of my gripes stem from lol

[Jane Pigliacelli · Rating 5 out of 5]

LETS GOOOOO IM SO EXCITED

[Emma · Rating 5 out of 5]

(Proper review to come)
Ugh I love this series so much and I desperately need more

[Jesicka · Rating 3 out of 5]

3.5

[Teresa · Rating 5 out of 5]

Gah!! That ending!!!

This book was a little slower, a little quieter, than the previous book but never boring! There is tension, action, danger, loss, love, change...

Airón goes through a lot of growth in this one. His and Tallu’s love deepens and we see even more beneath Tallu’s imperial façade.

My one and only complaint is a bit of a pet peeve - Hallu doesn’t speak like a traumatized 4 year old child, so much so, that had I not just read Shadow Throne King where he is described as 3 or 4, I would have thought he was a boy of at least 10 especially when it is stated he could sit the throne now should Tallu die. Like I said - it’s a pet peeve when children speak and act beyond their years without explanation, and none were given here.

That being said, don’t let it discourage you from reading the book. I loved the rest of it wholeheartedly and could hardly put it down once I started reading. I can’t wait to see where Kai Butler takes us next in the journey to escape the imperial legacy.

[Jessica Bardo · Rating 5 out of 5]

I am in love with this book and the series at large. It balances a deeply passionate romance with a complex court drama and a classic adventure story. It does a damn good job of it as well. Well worth a read or listen and well worth hanging on for the whole epic story.