[quote=@boomlover]
[@Savage] I was actually thinking about making an somewhat insane assassin, that writes poems. And has some rather "Dark" magical abilities.
[/quote]

Depending on those abilities, it is not off the table. The insanity aspect would actually tie in well to having some kind of powers. Perhaps your character has made some sort of deal with a cosmic entity, which has possessed him in a more symbiotic relationship instead of total control. Thus your character gains a small bit of this creatures power, at the sacrifice of their own sanity.

EDIT: Also I am realizing this course of action would provide you with the interesting option of "talking" to your otherworldly inhabitant within your own mind.