You already know what this is about. Just look.

I don't know where that thread of "About Vincent's Age" thing. You all wondered why he didn't age? Here is why.

Vincent's age, as provided in official materials, never changes: It remains fixed at 27, which is presumably how old he was when Hojo altered him. In contrast, the other main characters do age, which can be easily confirmed by comparing their ages in the game to those provided for Advent Children, which occurs two years after Final Fantasy VII. Further, Vincent's character designer, Tetsuya Nomura, has stated that Vincent was left immortal due to the experimentation conducted on him.