User blog comment:ChiroSamai94/so is Strong World canon?/@comment-3345720-20110204002210/@comment-1949750-20110204034732

The prologue is still about 22 years after. As for Shiki, we still don't know how strong he was in his prime. He may be legendary but doesn't mean he was powerful as Whitebeard or Rogers. I mean, he was beaten by Luffy in the movie.