In 1370 DR, the Doom Brigade was led by Gauntlet and accompanied by Skullpyr. They tried to stop the awakening of the Knights of the Crescent Moon, considering them a threat for its master. But they were unsuccessful.
The Doom Brigade worked as a very efficient war-machine thanks to telepathic coordination by Gauntlet. Each of the helmed horrors had some kind of individuality but they were totally loyal to Gauntlet and to Vaxall.