This is Survival of the Strongest
The Tournament of the Black Ring is a trial of the strongest warriors of the land, with the reward a guaranteed spot in the Twilight Brotherhood as a knight. All it requires is a fight to the death, winner takes all.
The father of a squire hires Alana and Karlyn Wildstar to retrieve his son from the deadly contest. The sisters infiltrate the tournament, and hey notice the judges create unbalanced rules for those in their favor. The crowd cheers as the matches rage on. The coin flows as freely as the blood. Now they must find the squire before they are locked a doomed gladiatorial combat.