Hela

Hela rules the Asgardian realms of the dead by right, not by conquest, and she resents every hero who treats that as villainy. Appointed by Odin to preside over Hel and Niffleheim, she collects the souls of Asgardians who die outside of glorious battle — and she has spent centuries scheming to expand the catchment, because a goddess of death with an underpopulated kingdom is a goddess without standing.

She is one of the few beings who can genuinely frighten Thor. Her touch withers gods, her Nightsword and Deathstalker cut through Asgardian steel, and she has killed Thor outright more than once, only to be forced to restore him. Kirby's design — the horned headdress, the half-corpse form beneath the cloak — has proven so durable that Thor: Ragnarok kept the silhouette almost exactly while rewriting her into Odin's firstborn daughter and Asgard's original conqueror.

Kirby and Lee introduced Hela during their landmark Journey into Mystery run, drawing directly on Norse myth where Hel is Loki's daughter. She became a recurring existential threat rather than a brawler, most memorably in Walter Simonson's run, where death and its bargains sit at the centre of the Thor mythos.

Later writers used her as a fixed point in Asgardian cosmology: she features heavily in Ragnarok cycles, the Siege of Asgard, and Jason Aaron's Thor, where the realm of Hel becomes a battlefield in the War of the Realms. Her defining trait across all of it is legitimacy — she is not an intruder in the afterlife, she owns it.