If you end up in combat with THESE Espada, you, unfortunately, will have to, besides, if you make the Bankai so powerful that you have to restrict the character from using it, then what is the point in having it?

Anywho, head over to the Bleach ITP OOC thread instead, it'll be better to keep the discussion going there.

And as said, 12th Division captain is taken, I don't know how active the Vice Captain is, otherwise, if you would tone down the power of the shikai a tad, he could easely be a strong third seat.