Board Thread:Questions and Answers/@comment-4310945-20140425001334/@comment-27392440-20160106031554

There are a few issues with those points though: 1-we don't really know what kind of power Yhwach gained from the Soul King so we can't really know if perception manipulation abilities from a guy who defeated Yhwach's omniscience while having most of his powers bound plus immortality and godlike strength may just win (Aizen still has an unrevealed bankai too). Also the royal guard didn't really intervene with Yhwach either until he got to the palace, sure they helped but Yamamoto had just died and that was a huge deal (whereas Aizen actually seemed to go out of his way to not kill captains and left Yamamoto for dead rather than killed him), and they may have came to help if Aizen hadn't seemingly decided to speed up his timeframes to invade. 2-the quincy conquered hueco mundo after they lost their strongest guys and by their own admission Yhwach had to personally fight Hallibel for her to lose. You also can't forget that, though the quincy do have some undeniably monstrous guys, there were only 10 espada that many seem to agree only lost because they each chose the worst opponent to fight and still almost won but more than double the stern ritter yet the very moment bankai was an option again the stern ritter were getting slaughtered. Also, Barragan alone could've annihilated even the elite guard stern ritter. 3-true we don't know how the soul king will power him up but at least SO FAR there's no evidence that he gets the stern ritter powers, just that he probably gets skills and spiritual power which is scary but not necessarily enough to beat Aizen. 4-many think that what we saw Ichigo use post soul palace training may not be bankai so Ichigo is far from showing his limits against Yhwach so it's unfair to compare him right now. You also assume that mugetsu wasn't his full powers, even though both Zangetsu were fused and seemed to realize they'd never see Ichigo again, so maybe old man Zangetsu/inner Yhwach figured he'd let Ichigo have full power that one time.

Also like I said in an earlier post, Aizen used the hogyoku on himself essentially so it's possible that it made him count enough as a hollow in power so Yhwach might succumb to the weakness to hollows that quincy are known to have if he took too long to kill the immortal Aizen. Though it's unclear it's very likely that a non-bound Aizen would win in my opinion,depending on what he gets from fusing with the soul king of course.