Ezalor, Spirit Form

{t}: You may exile a card from your hand, add
one mana of any color of that card's identity. You
may cast creatures and planeswalkers exiled this
way as long as Ezalor, Spirit Form is on the
battlefield.
{w}{w}{w}: At the beginning of your next upkeep,
Ezalor, the Keeper of the Ligh deals 4 damage to
all creatures you don't control.
At the beginning of your upkeep transform
Ezalor, Spirit Form.