Azmodan

"The Valrous manuscript lists Azmodan as the best battlefield commander of all demons, having defeated the angels many times in the Eternal Conflict across Pandemonium and the Prime Evils in the demonic civil war. If the Lord of Sin ever assaults our realm, we truly have much to fear."

- -Deckard Cain, referring to Azmodan Azmodan is a boss in the game Diablo III and Diablo III: Reaper of Souls. He is a Lesser Evil, but do not be fooled. Azmodan is one of the seven Lords of Hell, once imprisoned in the Black Soulstone. He was the last of the Great Evils imprisoned in the Black Soulstone.

Diablo III
In Act III, the nephalem comes face to face with yet another Burning Hell- Azmodan, Lord of Sin. He is very large with a gaping mouth and walks on spider-like legs. Azmodan also possesses a number of Sin Lieutenants, one of them being Cydaea, his consort and the Maiden of Lust. Azmodan lays siege to Sanctuary during Act III, sending swarms of demons from his lair in Arreat Crater. The nephalem must enter the crater and the portion of Hell within to destroy the Sin Hearts, and ultimately, Azmodan himself. Defeating him ends Act III and completes the Black Soulstone.

Trivia

 * Azmodan despises the nephalem, calling them "creation's greatest sin". He also has a low opinion of Belial.
 * Azmodan appears in Diablo Chess, taking the place of the knight on the demon side.
 * Azmodan returns in Heroes of the Storm as a playable character.
 * Azmodan once dreamed of being the sole lord of Hell.