Maimed tortured and forgotten

Long ago when he was only a little boy the dark lord attacked his town and killed all adult males.
He was captured along with his mother and two sisters.
One of his sister got separated from them.
To keep his remaining family alive he has to fight in the cage and bring profit to his cruel masters.
If he ever looses a war then his family dies.
So far he has never lost and has been bringing massive profits to his masters.
The are happy with him and promised to let go of his sister after 5 more fights.
But today he made a grave mistake; he got distracted while fighting.
It cost his masters a lot of cash.
The distraction was a beautiful girl he has never seen before.
His masters punish him by sticking a needle where it hurts the most; his family.
In his mind he can only blame the stranger who distracted him.
He his devastated and hungry for revenge.
How will he ever attain freedom or his much desired vengeance?