Actually, I would change Cripple into Revenge allowing you to murder summoned characters. And possibly have it leave murder scent, but for the max(1 day, duration of scent that perpetrator was summoned with).
As in you summon him with scent that has 0.5 day left and you leave scent that will remain for 1 day. You summon with a scent that has 1.5 day remaining and leave scent for 1.5 day.
Just a random idea.
If I didn't like someone, and this person happened to be of different nationality / color, then claeyt is the person who would immediatelly call me racist. He sees it everywhere.