Hymdall is the Gatekeeper of the Halls of Valor/Skyhold. When approached by the Battlelord, he tells them to obtain the Gjallarhorn in the possession of Svergan Stormcloak in Stormheim. Upon return, Svergan says that it was taken by the jormungarJorhuttam and the Gatekeeper sends the Battlelord to Highmountain to retrieve it. Hymdall then accepts as both Gatekeeper and champion to the valarjar in the war against the Burning Legion. Odyn then ordered the Gatekeeper to sound the Gjallarhorn to call upon his son Thorim. Unfortunately, the halls of Ulduar have been overrun by the armies of the Legion, and Odyn will send the Battlelord along with his champions to assist. Although Ulduar is safe from the Legion's onslaught, Hodir recklessly rushed into the Legion portal to chase after Lady Ran'zara onto the Legion world of Niskara. Hymdall awaits in Azsuna with the armies of Odyn, and alongside Thorim himself to rescue Hodir from the clutches of the Legion. After successfully in saving Hodir from Fel corruption, the Gatekeeper was able to open a portal back to Skyhold but can only maintain for a long period of time.
Within the Halls of Valor, he has been charged by Odyn with guarding the High Gate, the entrance of the Halls. After he is defeated by champions, he opens the gates to them and press on through to continue their trial. Hymdall is later fought as a bodyguard of Odyn, alongside Hyrja during the Trial of Valor. The gatekeeper questioned Odyn about "being lenient with these pets of his." Odyn told him and Hyrja to fight to their hearts content to be prepared for the task ahead. He is present after Helya has been defeated.