Lennithon, Arcane Incarnate

Partner, Flying, Flash
Exploit (When this creature enters the battlefield,
you may sacrifice a creature.)
When Lennithon, Arcane Incarnate exploits a creature, search target player's library for an
instant or sorcery and cast that card without
paying it's mana cost. Then that player shuffles
his or her library.
When you cast an instant or sorcery, you may
draw a card.