Armaddons are only encountered in Act IV. They are surprisingly quick for their size, and their brutal melee attacks may Stun the enemy for a short time.
In addition, Subjugators may mount Armaddons. If the two demons are close enough, a Subjugator will hop over the beast's back and remain immune to damage until the beast is killed (adding their attack to the mount, potentially being able to stun a hero and then launch a ranged bomb). When Armaddon dies, the Subjugator dismounts it unharmed and can fight on as normal.
- Aspect of Pain, Duriel's Darkrider (Gardens of Hope, 2nd Tier and Silver Spire Level 1)
- Slarg the Behemoth (Silver Spire Level 1)