Mors Murmer was summoned from a past dimension by Sabbat Vampires using dark magic.
He was rescued by members of M.H.I. and is still hanging out with them. Basically he has nowhere else to go and kind of likes them anyway. He is a skilled necromancer, enchanter and general mage so his presence is not entirely without use. Although he does tend to go a bit heavy on the beer and pipeweed.