User blog comment:Ichigosama/Similarities/@comment-5551986-20130730234516/@comment-11051098-20130731082501

I think he means that Aizen appeared to be an ally. I didn't suspect him to be an enemy at all, he seemed to be one of the kindest captains.

And if Yhwach was in a state where he was like frozen, for the 999 years he was sealed, so that his actual lifespan would be 9 years awake + an unknown number of years prior to being sealed, he could actually be going towards the end of his lifespan. As a Quincy, he is logically human-based, after all.