Koth, Hammer of the Arena

: As long as it's your turn, Koth, Hammer of the Arena is a 4/4 Human Berserker creature with menace that's still a planeswalker.
0: Reveal the top card of your library and put it into your hand. Koth deals damage to himself and to you equal to that card’s mana value.
-X: Koth deals X damage to any target and X damage to you.