Option when starting ritual to 'kill loser', ideally with perhaps saya +50% sucess modifier (so better if really fought to death, but is purely downed, you could still give the crwods the blood they want).
Bonus, if it was done more like old roman fights, and the crowd called out for mercy or death and you got the bonus for giving what the crowd wanted. Ideally with things like bloodlust, etc usually voting for Death, and kindness, pacifist, (high releationship with loser), voting for mercy