User blog comment:Xilinoc/Ch. 647 - THE THEATRE SUICIDE/@comment-27082083-20151016002357

Probably just speculating here, so I hope it's just entertaining speculation.

I read on another forum that the name of Shunsui's bankai is a reference to an 18th century Japanese play called "The Love Suicides at Sonezaki". In combination with the title of the chapter "Theater Suicide", it's safe to say that the function of his Bankai has something to do with theater, or perhaps turning reality into a stage, much as his shikai turns games into reality. It could be that everyone in it's area of effect become actors on this stage, and that the inevitable conclusion is mutual suicide. Perhaps Shunsui doesn't even have control over who is cast, perhaps Katen Kyōkotsu chooses the roles. It would seem Shunsui is willing to sacrifice himself in order to bring down Lille, if indeed they are the only two in range. I have a feeling Nanao will make an unexpected appearance, and we can assume there might be some animosity between her and Katen Kyōkotsu. It wouldn't surprise me wither if Ukitake showed up too. If this is indeed a double suicide drama we're about to read, it wouldn't surprise me if Ukitake jumped in to play a part, if it meant saving Shunsui or even Nanao from having to off themselves.