@Zerogodlike: It was to hype up the ability. Shonen battle anime and manga love to pull it off. Unless feats are shown to go along with what is claimed, then I have to call bollocks.
@taichokage: Difference being that when characters in Inuyasha hyped their abilities, Rumiko Takahashi actually would show that the characters were capable of pulling them off in many instances. On the other hand, Kubo has a bad habit of telling, not showing with statements and going for cool factor with his battles, which is why I find many character statements in the series to be questionable. If I can't trust the creator to show what characters can do for battle scenarios instead of being a braggart, then how do you expect me to seriously believe capabilities for a character that only have vague statements to ride on?
Do I believe Yamamoto is a Bleach top tier? Yes. Do I think he's THAT powerful with destructive capability? From what I've seen in the series, no I don't.