If you have no proof to support what your saying, then you can't say it is true, no matter what.
But if you want my proof, then the proof is that in the game of FF8, the characters specifically say that Ultimecia is a sorceress from the future. And think about where you went to go fight her. In the future.
Though when it comes down to it, none of this really matters. How long you live isn't really an accomplishment that really determines how accomplished a villain compared to things like destroying things, and achieving power.