Board Thread:General Discussion/@comment-8179648-20160310141759/@comment-11051098-20160313215337

Even if Askin is dead now and Kisuke doesn't use his Bankai any more fro now, he could still be using it later in a fight against e.g. Haschwalth, showing off some special ability or something.

But I agree, seeing as chapter 666 is up next, who knows what Kubo might pull out of his sleeve. He could take Askin's resistance to death to a new level, revealing him to be able to even survive having his heart torn out of his body and crushed while in Vollständig or for a limited time, forcing Kisuke to use a potential special ability after all, if he doesn't give Grimmjow some time to shine, which could be wise seeing as he is an Arrancar and presumably lethal to Askin.

I can imagine though that the Hollows being lethal part could be used right now, by having Grimmjow tear out his heart with his bare hand. The physical contact of an Arrancar's arm through Askin's chest and its claws crushing his heart could be what's needed to kill Askin for good.