Botan, The Midnight Star

Flying, hexproof
When you cast an instant or a sorcery from your
hand, if it was the second spell you cast in your
turn, creatures you control get +1/+1 and are
unblockable until the end of turn.
{1}{u}{u},{t}: Search your library for an instant or sorcery card and reveal that card. Shuffle your library, then put the card on top of it.