He did clearly state something like that at one point, that it was a lure to get ichigo out of Karakura town, and have soul society send reinforcements to bail them out and weaken the defence of the town.
Originally Posted by Twilit Prince
That said, i'd agree that he's probably exaggerating, and likely DOES need her ability for some odd thing or another that will come out in a revelation sooner or later.
what if she can create her own universes? or move across time?
While that's very plausable, I see it as the opposite. That he took her in to inspect her, test her, and then simply realized that he didn't need her after her secondary objective was completed. (Luring in Soul Society)
Originally Posted by Deathbringerpt
I doubt he'd leave her behind in there if was heading straight for the key and the throne before he was interrupted by the Captains.