Ur-Didact. For somebody that's supposed to be all big and bad he easily got killed. The Prometheans. They weren't fun at all to fight they were just annoying. They are bullet sponges that teleport around the map. I was playing on Legendary, but still. 343 should have realized that them having that much health, teleporting and some with shotguns. Was just dumb and dickish move to do. Did they even play test the game on the higher difficulties?