Thor: Ragnarok opens with Thor being held captive by Surtur, who he quickly defeats – but later on in the movie, Thor needed Surtur to best his sister, Hela, and he'll certainly struggle against Gorr the God Butcher in Thor: Love and Thunder without help. In over 10 years, the Marvel Cinematic Universe has explored many places not only on Earth but in other planets and realms. One of the heroes who has taken viewers to other parts of the universe is Thor, who has explored some of the Nine Realms as well as different planets in his solo movies.
In his third solo adventure, Thor: Ragnarok, the God of Thunder visited new planets and realms and came across never-before-seen threats. The movie’s main villain was Hela (Cate Blanchet), Thor’s older sister and goddess of death, who Odin banished from Asgard and imprisoned in Hel after she massacred many Asgardians and attacked him. Hela was no easy opponent, but before she was set free (which happened once Odin passed away), Thor had to defeat a seemingly bigger threat: Surtur, but he actually got rid of him quite easily.
Related: Thor: Ragnarok — Who Hela's Mother Is In The MCU
Surtur was a fire giant and ruler of Muspelheim, one of the Nine Realms. The source of his power was the Eternal Flame, which was kept in Odin’s Vault as the Allfather defeated him a long time ago and banished his entire race to Muspelheim. Odin’s purpose with Surtur’s defeat was to prevent Ragnarök, the event that would destroy Asgard. A prophecy stated that Ragnarök would take place when Surtur, empowered by the Eternal Flame, unleashed his rage upon Asgard. Without the Eternal Flame, Surtur was not as powerful as he used to be, so by the time he imprisoned Thor, he wasn’t that big of a threat.
Surtur
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