Kushala Daora, Storm of Steel

Flying
When Kushala Daora attacks, send target
creature back to it's controller's hand and give it
1 steel scale counter. If a creature has 3 steel scale
counters on it, exile it. If 2 creatures were exiled
this way, Kushala Daora has hexproof.
{w/u}{w/u}{w/u}{w/u}: Counter Target Non-Creature Spell.
If Kushala Daora has hexproof, this ability only
cost {w/u}{w/u}