Oh, the things a punster could do with that. But I won't, because I value my skin.

Anyhow...Given a large enough timeframe for the character to act in...any character will eventually become a Mary Sue/Marty Su. People will get better and better at what they do as time goes on. Give them enough time, and they'll become an expert at everything from needlepoint to advanced quantum mechanics.

I don't think it's entirely fair to judge a character 'in stasis'...look at FI Gryphon and you think 'Blatant self-insertion where he's a near god, GARBAGE!' but if you look at how the character was at the very start...and remember that there's more than four hundred years between them...