Earthbound Immortal Aslla Piscu (MZMI-EN048) [Maze of Millennia]

There can only be 1 "Earthbound Immortal" monster on the field. If there is no face-up Field Spell Card on the field, destroy this card. Your opponent cannot target this card for attacks. This card can attack your opponent directly. When this face-up card leaves the field, except by its own effect: Destroy as many face-up monsters your opponent controls as possible, and if you do, inflict 800 damage to your opponent for each monster destroyed.