So basically your character is Dexter? Minus the cannablilism thing of course.
Nope.
Dexter follows his code and tries to honor it even if he's really thirsty for blood.
My character can't stop himself.
When time passes the standard for his "justice" lowers, so just someone mouthing off to him can be the next victim.
So he is a little more muffed up in the head than Dexter is.

And if he can't find an evil person to perform his ritual on then he'll go into a blind rage and just kill everyone around him.
(I expect to end this character in the City Of Vegas, he'll go ballistic and get killed by securitrons. After that, he's done.)