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".
Marvel Cinematic Universe
Hela will appear in the 2017 Marvel movie Thor: Ragnarok portrayed by Cate Blanchett.