Bhaal

Not exactly a party god, nor someone you'd want to meet in a dark alley. His follwers however are extremely comitted or at least they should be. Bhaal is a dead diety of the Realms who still mantains a following for some mysterious reason. However, if you need to get someone out of the way and don't mind being a target later yourself necessarily you may be able to contact a follower or two of his.