Killing a villager in the circle for the summon demon ritual does not activate the ritual if you are possessing anything that is not a player, which if you are using the wandering spirit origin from requiem's integration with origins, will prevent you from obtaining a demon heart and progressing further in the mod. It works just fine when i tested it with a player body, but killing a villager in the circle with all of the correct conditions as anything else fails to start it.