User blog comment:Xilinoc/Ch. 684 - The Blade/@comment-27001684-20160728184852/@comment-5398287-20160728185931

You know, that's a legit theory I've had for a while now: we'd reach a point where Yhwach had killed off or otherwise incapacitated Ichigo, Aizen, Urahara, and pretty much everyone else who could be a threat to him, and he'd prepare to destroy everything...then Shinji would limp out from behind some rubble, be all like "What say we try this a second time...with style?", then activate his Bankai which would rewind time by either a few hours (the start of the Gerard fight) or back to the beginning of the war when Yhwach doesn't even have The Almighty, then proceed to inform everyone on exactly what they should do to take down some of the big players early on and thus end the war with far less casualties on the Shinigami's side. Bit of a pipe dream, but that would have put Shinji in a level of keikaku above even Aizen.