User blog comment:MrHatNClogs/Pedictions for 406: Deicide 8/@comment-1906999-20100531235751

I doubt it's a cacoon. I just don't really see Aizen hatching in a beautiful Aizerfly and flying to safety in the short amount of time left.

As far as Getsuga, remember Yuroichi's gloves/boots? That was something new, and Kubo quickly explained them at the beginning of the next chapter. I know it's not the same thing, but it's kinda the same scenario.