Rogue Infernal Slime

This creature must attack each turn if able.

When this creature leaves the battlefield, it deals
half X damage to each creature and each player,
rounded down, where X is equal to its power.

{r/g}{r/g}{r/g}: Exile target permanent from any
graveyard and put a +1/+1 counter on this
creature. You may use this ability only once each turn.