Hire Matthew as your mercenary to kill a member of the Gray Family.
Feeling some resentment? Matthew will, for the right price, kill a Gray Family member of your choosing (they may or may not return from the dead).
Buyer beware: This spell will not work on Matthew. He may also promise to comply with your wishes and kill someone else last minute. This matters because the spell also works on you.
*This service is cost prohibitive and therefore is without limits. Go nuts.