Slifer, the Sky Dragon

This spell can't be countered.
Flying
Slifer, the Sky Dragon enters the battlefield with
X +1/+1 counters, where X is the number of cards
in your hand.
Whenever you draw a card, put a +1/+1 counter on Slifer.
Thunderforce - Whenever you draw your second
card each turn, you may have Slifer fight up to one target creature.