She is based on the ancient Norse goddess of the same name.
Hela reveled in her rule, and always sought Asgardian souls to take to her realm, especially the souls of Odin and Thor. She created many plots to do so, once taking control of Valhalla, the Asgardian Heaven, for a short time. She once sent her armies of undead beings and spirits to conquer Asgard, during which the former Asgardian villain Skurge the Executioner, sacrificed himself to stop the enemy's progress at the Bifrost Bridge.
Another scheme involved her casting a curse on Thor, making him unable to heal wounds, but also unable to die. After many battles and suffering, Thor finally was destroyed by the Jormungand, and entered Niffleheim in the Destroyer armor. The armor's mystic power was too much for Hela, however, and she lifted Thor's curse and sent him back to Asgard.
Hela has often dabbled in the realm of mortals, manipulating and killing them as she pleased. She has often helped her father Loki in his many evil schemes. Hela was part of a meeting of supernatural demon/death rulers including Mephisto, Blackheart, Dormammu, and Satannish, who met to consort about the mystical mutant Magick finding the soulsword.
Powers and Abilities
Hela's true form is a shriveled, half-dead being, but her cloak revives her and gives her full power. Hela has great magical power over life and death, and can drain the life from anyone she touches, as well as age them quickly with mystic bolts. She is extremely powerful in physical, mental, and magical combat, able to go toe-to-toe with Thor. She is a master at manipulating magic, and can use it to levitate, time-travel, use astral projection, and create illusions, among other powers. She is also an accomplished swordswoman, using her blade "Nightsword".
In other media
The Avengers: Earth's Mightiest Heroes
Hela appears in The Avengers: Earth's Mightiest Heroes episodes "The Fall of Asgard" and "A Day Unlike Any Other", voiced by Nika Futterman. After Captain America is blasted into Hela's realm, she tries to convince him to stay among the dead with his fallen comrades from his days in World War II. However, realizing that Loki would betray her someday, Hela agrees to teleport Captain America to Asgard to fight Loki, telling him that, if he falls in battle, his soul will belong to her. After he returns to Earth, having defeated Loki with the other Avengers, he sees Hela' reflection in his broken shield just before he is knocked-out and replaced by a shape-shifting Skrull spy.
Hela appears in the Avengers Assemble episode "Valhalla Can Wait", voiced by Vanessa Marshall, striking a deal with Loki to be entertained by watching Thor and Hulk battling each other in exchange for the Horn of Hela, which could control Hela's skeleton warriors. She is the ruler of Valhalla in this incarnation. After the two take a dive against him, Hela deems Loki the winner and has a giant skeleton take Loki to Valhalla.
Marvel Cinematic Universe
Main article: Hela (Marvel Cinematic Universe)
Hela will appear in the 2017 superhero movie Thor: Ragnarok, portrayed by actress Cate Blanchett.