Circu, Dimir Lobotomist - [Foil] Ravnica: City of Guilds (RAV) C21 each of those creatures has

each of those creatures has "Whenever this creature deals damage to an opponent

Whenever an opponent casts an instant or sorcery spell

Spitting is the customary greeting between a creature and its magical impostor

Untap Victory Chimes during each other player's untap step

Circu, Dimir Lobotomist - [Foil] Ravnica: City of Guilds (RAV) C21 each of those creatures hasWhenever you cast a blue spell, exile the top card of target player's library. Whenever you cast a black spell, exile the top card of target player's library. Your opponents can't cast spells with the same name as a card exiled with Circu, Dimir Lobotomist.