Sergeant Dalen was one of the defenders of Bastion's Keep. During the siege on the keep by Azmodan, he encountered The Nephalem, who had succeeded in lighting the signal fires. A vision of Azmodan appeared to mock their efforts, but The Nephalem assured Dalen it was just a vision, designed to undermine their morale. With that done, Dalen directed The Nephalem to the Stonefort, where the keep's catapults could be raised.[1]
In-game[]
Dalen is an NPC in Act III of Diablo III. He is found at the end of "The Siege of Bastion's Keep" quest, and starts the "Turning the Tide" quest.