Board Thread:General Discussion/@comment-24189673-20131120064700/@comment-27083778-20151016141842

Mine's merely a guess. His shikai makes children's games come true, he also admits he has no control over the kind of games his Zanpakutō chooses. We also know that he shouldn't reveal his bankai when there are other people around. Maybe his bankai forces the players to play the ultimate game, a game in which the winner claims the life of the loser?