User blog comment:Ichigosama/Similarities/@comment-5551986-20130730234516/@comment-10961564-20130731094140

well Aizen was a little too good at the start and i suspected him to be something else....Yhwach isn't your normal day Quincy, he's their monarch...

When someone wakes up from a state when they were like frozen, their body is as young as it was, no matter how much time has passed..also 1000 years ago, Yhwach and yama-ji seemed to be about of the same age and as yama-ji lived for another 1000 years and would have lived longer(though he was a shinigami and their lifespan is abnormally long)...considering that, Yhwach looks to be in his prime like Ryuken so natural death ain't was is expected