Assur

Assur was a baron of the Burning Hells. The favored of the Lord of Terror, Diablo. He had bright and glowing red eyes, and horns protruded from his shoulders, elbows and knees. He wore a primitive loincloth, a belt and a giant sword. On his chest was an emblazoned glyph, a blessing from Diablo that can only be cast once a millennium, that made Assur invulnerable to the hand of any living thing.

Assur was slain by Siggard at the city of Brennor after Assur's army had initially undertaken a successful siege.

Trivia

 * Assur is an East Semitic god, and the head of the Assyrian pantheon in Mesopotamian religion.