Mage of the Dim Caves

Haste
Unblockable
Frenzy X (Whenever this creature attacks and is not blocked, this creature gets +X/+0 until end of turn.)
Whenever Mage of the Dim Caves deals combat damage to a player, Fateseal X(Look at the top n cards of an opponent's library, then put any number of them on the bottom of that player’s library and the rest on top in any order.)
At the beginning of your end step, exile Mage of the Dim Caves.