Sauron

Indestructible
"Sauron was become now a sorcerer of dreadful power, master of shadows and of phantoms, foul in wisdom, cruel in strength, misshaping what he touched, twisting what he ruled, lord of werewolves; his dominion was torment."
-Description of Sauron, in The Silmarillion, Quenta Silmarillion: Of the Ruin of Beleriand and the Fall of Fingolfin.