Dark Warlord by Cynthia Sax

Battling the Barbarian…
All Chamele Warlords have a destined mate, a gerel they are fated to spend their lifespans with. Batu, being genetically enhanced, believes he’s the sole exception. He devotes himself to battle, is resigned to living a solitary life, dying with swords in both of his hands.
Then he sees her.

Genine is a warrior female intent on protecting her loved ones. To keep them safe, she must face Fighter Batu in the ring. If she loses to the barbarian, she becomes his to do with as he wishes. And he wishes her to submit to his deep voice, rough touch, passionate kisses. If she defeats Batu, she will have to kill the one male she was destined to love.
This story was previously part of a box set.
Dark Warlord is a short companion story in the Refuge series and is meant to be read after Dark Flight