Originally Posted by kael03
Not a plot hole (and not for the reason ck gave). Ichigo's Bankai is a compression of the Bankai's power to the form of a katana. Yamamoto's bankai doesn't change the shape of his sword, but expands the power of the flames.
Ichigo's sword isn't the only one that is small for bankai. Komomura's sword doesn't change when he uses bankai. Tosen's didn't change, Gin's didn't change, Toshiro's doesn't change.
I didn't mention the sword size, I meant Bankai size. Komomura has a giant, Tosen has a whole field, Gin has a giant sword. Toshiro's has huge wings and turns dragon-like.
and expands? more like compresses. It's in the chapter just now dude. It's just like Ki/Chi, when you compress it, it turns more powerful and deadly.
I just point it out since nobody else seems to and is caught in the awe of its awesomeness. It doesn't matter too much though since Kubo is scheduled for a betrayal once he finishes off Yamamoto, but meh, we aren't there yet so anything can still happen.