when a killer among us enters the battlefield, create a 1/1 white human creature token, a 1/1 blue merfolk creature token, and a 1/1 red goblin creature token. then secretly choose human, merfolk, or goblin. sacrifice a killer among us, reveal the chosen creature type: if target attacking creature token is the chosen type, put three +1/+1 counters on it and it gains deathtouch until end of turn.