Hela is the main antagonist of Thor: Ragnarok. She is the first born daughter of Odin, which makes her the elder biological sister of Thor Odinson and adoptive elder sister to Loki Laufeyson. She is the goddess of Death and heir to Asgard's throne who is bent on taking over Asgard with her own army of Berserkers at her side, rebuilding it in her own image and conquering the entire universe instead of simply Nine Realms.
She is portrayed by Cate Blanchett.
Hela started out as the firstborn child and sole daughter to Odin and Frigga. She served her father as an executioner and leader of the Einherjar in Odin's plot to conquer the Nine Realms. She served as a loyal, faithful, and dutiful servant to her father, even being so pure as to wield Mjølnir. However, as the years went by, Hela start to develop her ambitions and powers to a degree that would grew beyond Odin's control. Having noticed his daughter's ambitions as well her new warmongering and bloodthirsty behavior, Odin, who had finally realized that peace is the true way to unite the Realms, was forced to fight Hela when she massacred anyone who tried to oppose her and attacked her own father. Able to defeat her but incapable of killing her, Odin decided to dispose of Hela by banishing her to a realm called Hel, where his life force would be the only lock to keep her from escaping.
Hela once tried to break free from Hel, which prompted Odin to send female Asgardian warriors called the Valkyries to stop her. Hela first send out Necroswords to kill some of the Valkyries and then engaged the remaining Valkyrior Warrior Maidens and overpowered them all,killing almost all of the Valkyries. Odin was ultimately convinced that he himself must personally intervene, having apparently been convinced after apparently waiting for the Valkyries to return that Hela is too much for them. Odin then personally entered Hel and was able to overpower Hela and re-imprison her, but save for Brunhilde, the leader, all the Valkyries perished in the battle.
Odin then proceeded to write out Hela from all of Asgardian history, even replacing the murals of her conquests with those of his other children.
Several years following the deaths of Frigga, Malekith and the Dark Elves, Thor battled against the fire demon Surtur, who foretells him of an event called Ragnarok that will destroy all of the Asgardians once his crown is united with the Eternal Flame within the city. Undaunted, Thor defeats Surtur and his demon horde before taking Surtur's crown, believing that he has averted Ragnarok.
However, Odin dies of old age after being found by Thor and Loki in Norway, but not before he tells them about the existence of Hela to them. Following Odin's death, Hela was able to escape from Hel through a portal-like gateway, musing that she would have liked to see her father die in which during their humorous encounter that when Thor introduces himself as her sibling, much to her shock in which she replied that he does not resemble Odin after all. When Loki proposed a truce, she sarcastically stated he sounded more like Odin. Forgoing all civilness, Hela then demands her brothers to bow down before her and acknowledge her as their new queen. Thor and Loki defiantly refuse before the former throws Mjølnir at Hela, but unfortunately, she catches the hammer and destroys it instantly with her bare hands before adjusting her headdress. A shocked Thor and Loki then attempt to escape to the Bifrost Bridge, but Hela pursues them and easily throws both of them out into space, leaving them to crash-land at a nearby planet named Sakaar (ruled by the notorious Grandmaster).
With both Thor and Loki banished, Hela took the opportunity to take over Asgard by eliminating the Einherjar (the elite army of Asgard) along with the Warriors Three (Volstagg, Fandrall, and Hogun) and eventually appointed a downtrodden Asgardian named Skurge to serve as her Executioner after the latter spared him upon her arrival in Asgard in which she killed Volstagg and Fandrall with ease for resisting her. Upon destroying the remaining army and with Asgard left defenseless, Hela then swiftly assumed the throne and destroyed the murals that Odin created which she described it as "lies" upon seeing within its murals that depicted peace treaties, festivities and exchange of gold and goblets; which its destruction revealed several of its darker murals that foretold her history before proceeding towards Odin's Vault with Skurge in which she discovered several artifacts stored in there as she declared the Infinity Gauntlet "fake" in which she deduced that the latter was just a mere replica (the real Infinity Gauntlet was wielded by Thanos), the Casket of Ancient Winters "a useless object", viewed Surtur's crown as 'smaller than she thought', became interested in the Tesseract but proclaimed the Eternal Flame the greatest of all. She smashed through the floor to the mausoleum underneath while wielding the Eternal Flame as she demonstrated to Skurge her true powers before descending down and used the Eternal Flame to resurrect her dead pet Fenris Wolf and her own army (known as the Berserkers) to cement her new role as Queen of Asgard.
With her subjugation of Asgard complete, Hela plans to use the Bifrost Bridge to expand the Asgardian empire through the universe, but Hemidall (the sentry of the Bifrost Bridge who was banished earlier by Loki) secretly returns as he covertly steals the sword controlling the bridge rendering it useless before hiding away with the rest of the Asgardian citizens to form a resistance against Hela's reign. A furious Hela then orders Skurge along with her troops to take down the resistance so that she can use Hemidall's sword to activate the bridge and proceed with her plans.
Eventually, Hela, Skurge, and the Berserkers manage to discover the location of the Asgardian resistance with an information from a Asgardian civilian who exposed the location in which he revealed that the resistance took refuge on an old fortress within Asgard after Hela coldly ordered Skurge with a threat to execute a young and innocent Asgardian woman and upon hearing the plea of the civilian which led her to promptly convince Skurge to spare the woman.
Using the information that she gained from the Asgardian civilian, Hela and Skurge, along with the Berserkers, then begin their assault on the old fortress (by tearing down the ancient gate with her spikes) where Heimdall is hiding with the Asgardian civilians but the echo from Asgard's throne room that was sounded by Thor's hammering of an iron staff prompted her to return and confront him in which she was surprised that Thor managed to survive from their encounter in the Bifrost Bridge while Thor sarcastically stating of her actions by tearing down the murals as "redecorating" which he discovered the now revealed darker murals upon his arrival earlier while Hela replied that was "father's solution to cover it up" then demanded Thor to leave the throne but he refused which led to engaging in a fight with him, thereafter. This distraction also allowed Heimdall to evacuate the Asgardian civilians from the old fortress and led them to return to Asgard through the Bifrost Bridge only to be cut off from behind by Skurge and the Berserker army and in front by the enormous Fenris as both fronts began to attack them; However, the battle's tide is turned when Loki returned after defeating the Grandmaster's forces and escaping Sakaar (with the help from the Hulk and several gladiators) on one of the Grandmaster's giant ships. It also turns out that one of the gladiators named 142 happens to be the sole Valkyrie who previously survived Hela's attack during her previous attempted escape from Hel. The Hulk and 142 then proceed to fight against Fenris, Skurge, and the Berserkers while Loki and the gladiators evacuated the remaining Asgardians on the ship.
With the defeat of Fenris and the Berserker army faltering, the duel between Thor and Hela continues to intensify, but he loses an eye in which Hela was able sliced it with ease before subduing him and then Thor receives a vision from Odin that only Ragnarok can defeat Hela. It was then Thor realized that the true meaning of Asgard meant for protecting its citizens, not its land. Then, he eventually regained his full power by striking a lightning towards Hela, knocking her down in the process while at the same time, taking down several Beserkers in a massive lightning blast. Deciding to let Surtur bring about Ragnarok, Thor and 142 distract Hela while Loki takes Surtur's crown and unites it with the Eternal Flame (per Thor's orders). Witnessing the heroes and the remaining Asgardians escaping on the giant ship, an angry Hela attempts to stop them by pinning the ship with her spikes, but a repentant Skurge redeems himself by allowing the Asgardians to escape while taking down several Berserkers (who were attempting to board the ship and attack the Asgardian citizens), though Hela kills him with a knife in retaliation. Hela taunts Thor that even with his full power, she is too powerful to defeat and that she's willing to hunt down and kill all the remaining Asgardians to complete her goal. However, Thor taunts Hela by revealing an arising Surtur, who starts destroying a large portion of Asgard, leaving a shocked Hela to realize that she's been distracted. This allows both Thor and 142 to stab Hela in the chest and send her down into the river before escaping with Hulk, Loki and the other survivors. Unwilling to let Asgard be destroyed (as it is the source of her power), an infuriated Hela arises from the waters and tries to destroy Surtur by impaling him with a multitude of spikes, but Surtur is immune to them and taunts Hela by laughing back at her, much to Hela's distraught. Surtur then violently shoves the tip of his mighty flaming sword down on a horrified Hela, killing her in a blast of green energy and incinerating her remaining Berserkers in the process. Thor and the survivors then all watch as Surtur fully thrusts his sword to destroy Asgard, killing himself in the process.
With Hela and with her forces vanquished for good, Thor (taking over as the new King of the Asgardians) decides to build a new Asgard for his fellow people on Earth.