Fifth Battle of the Diamond Gates

The Fifth Battle of the Diamond Gates was one of the few times the Prime Evils truly worked together, and their combined might almost felled the gates leading to Heaven itself. Just when it seemed that the Prime Evils would win the Great Conflict, they were so confident of their impending victory that they turned on each other, fighting over spoils they had yet to win. The attack was halted as the forces of Hell battled each other, and Izual rushed to the defense of the gate, beating back the Evils and their hordes with his angelic runeblade Azurewrath, and valiantly saving the Diamond Gates, and Heaven.

The demon Draorm is known to have participated in this battle, along with Tyrael.