Wicked Devil

by Sienna Cross

He killed her fiancé. She wants revenge. But loving the devil might be her greatest sin.

More coming soon!

Wicked Devil is the fourth and final steamy story in the dark and decadent Ruthless Heirs series. Each book is a standalone novel complete with a HEA, of course, because even villains deserve a happy ending. This series is the next generation of the Kings of Temptation, but it is not necessary to read those stories first. Please this is a dark romance novel with scenes that may be triggering and sexually explicit in nature.

Kings of Temptation
Ruthless King
Savage King
Brutal King
Wicked King

Ruthless Heirs
Ruthless Guardian
Savage Prince
Brutal Heir
Wicked Devil

Kindle Edition

Expected publication March 10, 2026

About the author

Sienna Cross was kidnapped by mobsters, saved by her super-hot step-brother, then forced into an arranged marriage with a billionaire. From there, things got really interesting… She loves to write about dark, morally-gray alpha males and the captivating women that bring them to their knees. For all the inside info, join Sienna Cross’s Heartbreakers on Facebook, like her page, and follow her on Instagram and Tiktok. She has a thing for stalkers ;)

Reviews

[Nicole · Rating 5 out of 5]

As the heir and tech genius to the Gemini Empire, Matteo is used to having enemies coming for their pound of flesh, but when a masked assassin catches him off-guard in his office, it throws him for a loop. Although her identity remains hidden, her appearance sends him into a spiral, bringing up memories of a summer he swore to leave behind, but hasn’t been able to forget. When repeated encounters with his blonde nemesis escalate, finally putting his loved ones at risk, he tries to catch her, only to see a ghost of his past brought to life. Now he’s torn between loyalty to his family, and a chance to keep the promise he broke long ago.

Caitríona was sent to New York by her family to end Matteo as revenge for the death of her fiancé, but every time she’s gotten close, she hesitates, unable to forget her first love, despite how he left her four years ago. When her family gives her 24 hours to finish the job or find herself on the wrong side of a gun, she has to make her move or run forever. When Matteo finally sees her face and realizes who has been chasing him, instead of retaliating, he offers to help. Now she needs to decide whether she can trust him now when she couldn’t back then, and whether letting him help will be worth the risk that he’ll ruin her all over again.

I received an early copy of this book from Greys Promotions and it was so worth the wait. Having read the preview at the end of Brutal Heir, I knew the premise of the story, but I did not expect it to hurt so much, and boy did it ever. Right from the beginning, I was waiting for Matteo to realize that Cat was the woman after him, and the flashbacks of their time in Sicily had my heart breaking right along with them. I loved how quickly Matteo realized that he had been in love with Cat all along, but although she loved him back, she also couldn’t trust that he wouldn’t abandon her again. Their past was woven into every decision they’ve made since, but some hurts are too big to forget.

[Jaime Trupp · Rating 5 out of 5]

If you’ve been reading Sienna Cross’s series, then you already know she delivers intensity, heat, and fiercely loyal men—but Wicked Devil somehow raises the bar even higher.

Matteo and Caitríona absolutely wrecked me in the best way.

I love all of Cross’s books in this series, but this one was different. This one was special. Beneath the power plays, danger, and undeniable chemistry is a deeply emotional story about loyalty, sacrifice, and choosing love even when it feels impossible.

One of the things I adore most about this series is the family dynamic—Matteo’s cousins and the way their stories interweave throughout the books. The loyalty among the cousins isn’t just background noise; it’s foundational. It shapes who Matteo is and influences the choices he makes.

While Wicked Devil can absolutely be read as a standalone knowing the cousins’ journeys makes every interaction hit
Sienna Cross didn’t just write another installment—she wrote something that lingers. And for me, Wicked Devil will be the one that tugged the hardest at my heart.

[catb.x0x0 · Rating 5 out of 5]

I don’t have words for the way I devoured Matteo and Cat’s story. I don’t recall Sienna Cross’s words having ever been more poetic and beautiful. As I’d read and re-read the passages in this book it's so easy to forget the mafia genre and the violence amongst the pages, only to focus on the love story that haunts both of our main characters and the emotions that flow from them. This story is just as precious as it is vicious and absolutely deserved all the stars!

[Reading is escaping reality · Rating 5 out of 5]

Trying to get revenge from the one person you once loved, harder than what she thinks. He thought he would never see her again, but taking care of her late fiancée changes things for them. Revenge, love, never hate. The secrets, the love, and everything in between. This was absolutely amazing!

[Catherine Rayne · Rating 5 out of 5]

I loved this story. I couldn’t put it down and devoured it in one day. Sienna never disappoints and I’m thinking about starting over from the very beginning with the parents’ books. I wasn’t ready for this book to end. Five stars!