User blog comment:Xilinoc/Ch. 652 - THE THEATRE SUICIDE SCENE 6/@comment-29183117-20151119174553/@comment-11051098-20151120002840

Seeing as Gerard is The Miracle, he could very well have a level of power, or his power be of a nature, that could require more than one Bankai to defeat.

The Miracle is such a vague and possibly "far out there" epithet that who knows what it can do and to what extent.