[ICWiener]

Common Lisp: maybe an Animagus, like Sirius Black. Or maybe Alastor Maugrey (Mad Eye), who is quite powerful but is not necessarly attractive.

[ChuckMcM]

I'd definitely make Lisp Mad-Eye Moody, terse, and complex, but quite powerful.

[bloaf]

I like the Sirius Black comparison. Was influential during the previous generation's rise to power but broken promises (A.I. Winter) forced him to scrape by in the background for a while. Nowadays people who know him realize his power, but to most people he is a shady character from the past.