[Dilla]

I'm keeping up with an interesting Naruto/Kamen Rider crossover where Naruto, in a world where Riders have made shinobi obsolete, receives the Decadriver and is trying to use it to destroy all Riders because they destroyed his dream.

Or something like that. I don't know a single thing about Kamen Rider but it's maintained my interests.

Anyway, the point of all that is to show an example of what I'm looking for, which is an anime that has a main character who intentionally becomes something he hates in order to try and shut it down.

The only thing I've watched pertaining to this is Code Geass, and I didn't really like Suzaku all that much, so I should receive something new to watch here easily.

I guess unintentionally works as well, as long as it's like a vampire hunter that gets bitten and turned, but continues hunting them or something (Natsuno from Shiki is an example of this, I guess).

Edit: And post-2000.