Slifer the Sky Dragon

This spell can't be countered, put a +1/+1 counter
when enter the battlefield.
Flying, hexproof, indestructible, vigilance.
Gain +3/+3 for each card in your hand.

Whenever a creature enters the battlefield under
an opponent's control, put a +1/+1 counter on Slifer,
then fight that creature.

Whenever Slifer deals damage, draw a card.