... Who said you can't have multiple??? Â :P
No, seriously, out of those two...I'd go for the 2nd: "I am The Doctor" as well. Because really a theme is supposed to answer the question "Who are you?" and, as far as I know... Wiz is not his tradgety... but it is part of him, and what makes him the hero he was/is/(will be?) Â As for #3, Wiz's true self is not Mad either. I think (of course, I don't know; This is your character. :P ) that his madness is a cover for his stronger emotions. Or perhaps a result... not sure.
Wiz is foremost a hero, motivated by his past expirences. At least, that's what I get, when I reflect on what's been written. Thusly, I like #2 best. :D