Well, it isn't! :p
Okay, here's the last clue, since this is practically giving it away:
The character has purple eyes, brown hair, and usually wears a gray trenchcoat (at least in the anime).
Sorry; it's one of the few shojo books I read, and the only shojo I've read with shinigami!
Wait . . . is it Tsuzuki from Descendents of Darkness?
I stumbled onto the answer quite by accident! I was watching "The Flying Car" on YouTube and a friend said, "Oh, that's Descendents of Darkness!" So, I checked it out and went, "OH MY LORD! THAT'S IT!"
My turn (why not another bishonen?):
Occupation: freaky, sadistic doctor; unofficially high-ranking member of a secret organization
Public Persona: people see this person as a kind, intellectual man of science; he's often "helping" them; behind the scenes, he experiments on them . . . this usually ends in death
Yo creo que nosotros necesitamos ayuda con eso. **insert upside down question mark** Por favor?
EDIT BY HAMMER...please use English.
Rough Translation: I believe that we needed aid with that. Please?
I understood you; now besame, Wolfy. :kisser: Just kidding. Let's see . . . a clue that won't give everything away. This character was born illegitimately, so he hates his brother, who inherited everything.
i wanna say tucker from Full metal Alcehist! Is it?
Hmmm....Is it Dr. Muraki from Descendants of Darkness?