It's clear now. Execute the Shaman. The Cop is 100% not Mafia. The Man used his own ultimate ability; the activation of the Orc's ultimate would look different (as I think). And I'm not saying that the Cop can't be Mafia. But if he is the Man, then the chances of the Orc being the main host of Kenkael seem doubtful to me.
Shaman, could you explain your suspicions in more detail?