Surt rules over the Vanir from his palace in Jotunheim, the realm of ice, situated in the North of Asgard and protected by a seal which can only be broken with the Accursed Flame Gem. The ongoing feud between the Vanir and the Aesir eventually escalates into Ragnarok, which provides the setting for the game's plot.
If Ending B is triggered, after supplying Asgard with enough Einherjar and repairing the Accursed Flame Gem, Lenneth is tasked with infiltrating Jotunheim Palace, while the rest of the Aesir distract the brunt of the Vanir forces. She eventually finds her way to Surt's throne room and challenges him. He accuses Odin of deviousness, but does not expound on this statement and meets his end at Lenneth's hands.
If Ending A is triggered, after Lenneth sends Lucian to Asgard, Loki distracts him, steals the Dragon Orb, which Odin had retrieved from Midgard, then kills him and blames the theft on him. He then brings the Orb to Surt. To ingratiate himself with the Vanir, he says that Surt is known as a man of justice and that he believes in justice himself. However, in order to win the war, Surt needs power, as Odin holds three of the Four Treasures. Loki then offers him the Orb, as well as Fenrir and Bloodbane, the dragon who is said to have swallowed the fourth Treasure, the Demon Sword Levantine. However, while this would effectively even the odds between Odin and him, Surt refuses to consort with monsters. Seeing that his negotiations have failed, Loki then uses the Orb to kill Surt.
In Norse mythology, Surt is a jötunn (giant). While the home of the jötunn is Jotunheim, he rules over Muspelheim, the land of fire. The jötunn are opposed to both the Aesir and the Vanir, and, during Ragnarok, Surt is destined to defeat Freyr and engulf the world in flames.
Surt's name comes from the Old Norse word svartr, which means "black". As he is associated with fire, this could be a reference to his complexion being scorched by flames.
- Surt is voiced by the same actor as Jun and Janus.
- In the game, Surt is a Vanir, and while he does appear to be much taller than the other Vanir, this difference is never specifically addressed. Moreover, while he does retain his elemental affinity to fire - as is obvious from his attacks - Jotunheim is clearly depicted as a land of ice. To further add to the confusion, the in-game description of the Citadel of Flame refers to Surt as the Lord of Muspelheim.
- While Niflheim is also waging war against the Aesir during Ragnarok, there is no indication that Surt is allied with Hel.