Nixi, Burned

Haste
Whenever Nixi deals combat damage to a player, put a +1/+1 counter on each creature you control, and another +1/+1 counter on Nixi.
Remove a +1/+1 counter: Nixi can't be blocked this turn.
When Nixi leaves the battlefield, it deals 4 damage to target creature. It cannot be regenerated.
I have felt what it is to melt in boiling lava. Now it's your turn.