Breeder by Mila Zahn

Stolen from her life on earth and given to the beast as his prize, will love bring them both the freedom they crave?
Kaiya: Forced to become the mate of the planet’s deadliest gladiator, I will do whatever it takes to survive. Even if that means unlocking the heart of the beast they call Madness.
Selonius: My heart turned to stone after deadly Thrycene forces decimated my home world. I was sold to the slaver Dal-Hex where I learned to survive in the fighting pits on Planet Barbarian, rising to the top because of my ruthlessness.
Thrown together in captivity and forced to breed, the unlikeliest of circumstances led to one of the greatest loves found across the universe.
One that would spark a revolution and shake the foundations of the very empire that sought to destroy them.