USS. Cassin, Blind Phoenix

USS. Cassin, Blind Phoenix can't block.
When USS. Cassin, Blind Phoenix enters the battlefield, unless it was cast from your hand,
put a +1/+1 counter on target creature.
Whenever USS. Cassin, Blind Phoenix dies, exile
it. You may cast it as long as it is exiled this way.
"I was a mistake, yes. But I was also a lesson."
-Cassin