Board Thread:General Discussion/@comment-24189673-20131120064700/@comment-26420452-20131120110615

I don't think Shunsui's Bankai has to do anything with simply shadows. Kageoni is just one of the "games" of his Katen Kyōkotsu.

Knowing that there's no Zanpakutō that has unrelated abilities of Shikai and Bankai, his Bankai will still have the children's games theme. Shunsui explains about his Shikai that anyone who gets inside the boundaries of its Reiatsu is forced to play. I hypothesise that in Bankai, its Reiatsu is huge (it has to be, doesn't it?) and many more people might get involved in the games, so it's very risky to use it in others' presence. Plus, the games must become more vicious and have trick rules. Appeareance-wise I don't have any idea, but it might some reference to the oni.