Mordred, Knight Camelot

When Mordred, Knight of Camelot enters the battlefield, deal 3 damage to all enemy creatures.

When Mordred, Knight of Camelot dies,
return it to the battlefield with a -1/-1 counter.
When Mordred, Knight of Camelot has
exactly 0/0 returning to the battlefield, exile Mordred, Knight of Camelot.