possibly his bankai is stronger if he was hurt before releasing or he has to play his zanpakutou's game and take a big risk of sorts before it will let him release his bankai?
i had another thought on this but now i forgot >_<
but i kinda doubt my first idea but not very sure about my second one either

You can only be cut by the color you announce, or the color the enemy announces.

that's pretty shitty power

Not really. One can easily defeat enemies with the technique, especially dumb ones.
It is more complex than what I had stated, though.

This post was edited by Epion on Sep 17 2009 01:17pm

That and if he doesn't explain the details to the game his Zanpakto likes to play the enemy would be screwed.

exactly...

not completely since most enemies would probably be like "wtf does he mean by my turn?"
so it would probably be stuck on there turn for awhile

Not if he calls a color they have but he does not. This way, he cannot be damaged, while he hacks them to pieces

but they take less damage that way like when he called gray yet his arm suffered next to no damage but it felt worse

Just hit him a bunch of times.