He has no personality, is in direct opposition to the main goal of the cast as a whole(who are noted to need to be able to work together), and does not have the means to fight the other characters. He'd die in the first few posts. I have to be honest here.

A maniacal serial killer is also a poor choice given the cast needs to be able to work together.

Finally, the premise of the RP is everyone working together(even if they don't like each other in a few cases), so having someone just dropping by for violence doesn't really work.