@mythandmajesty
Merlin had been captured, clasped in irons and dragged back to a castle. It seemed there was a rather tight operation there, nobles betting on captured men's lives as they were forced into battle. The man in charge quickly determined that Merlin was not a fighter, almost deciding that he was useless. Merlin winced, flinching as talk started about simply dispatching him right off.
But, then a somehow worse idea started circulating. He could still be used to entertain. Merlin was dragged off, struggling and pleading behind a gag. He was encased in darkness, chained down with his bottom half on display through a little window. He was forced to kneel, ass up and waiting. Merlin sat through the entire fight as they decided that their champion deserved first claim.