Avi, Aven Cardinal

+2: All Bird creatures gain a +1/+1 counter and gain lifelink until end of turn.
-2: Summon a 1/1 flying Bird creature token with "When this creature dies, you may play an instant or sorcery without paying the mana cost."
-15: Search your library for X Bird creatures, X being how many instants or sorcery spells are in your graveyard, and place them onto the battlefield.