Hela, the comic character, has been around for almost as long as Thor. Based on actual Norse mythology, she's the ruler of two different underworlds and constantly trying to make it three. She's the daughter of Loki and a frost giant, and she's also sister to Fenris, the giant wolf. Among her many exploits, she's killed Odin, killed Thor, worked with Thor, hooked up with Thanos, and palled around with the likes of Dormammu and Mephisto. She's resurrected almost as many souls as she's taken, including Odin's, because she's not a monster and is, in fact, a multifaceted goddess of antiquity who does what she wants. Nobody -- except for that one time she was briefly mind-controlled by Nazis -- puts Hela in a corner.
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Thor: Ragnarok, meanwhile, starts with Hela in a corner, locked away for most of creation. Instead being a vaguely reasonable being just trying to do her best for Hel, she's a revenge-fueled murder-lady who's good with knives. Her entire comics' -- and Old Norse -- backstory is erased, replaced with one "borrowed" from another character entirely: Angela, a character originally created for Spawn, who Neil Gaiman sold to Marvel cause he was pissed over Todd McFarlane's shadiness. Marvel then turned Angela into Thor's long-lost sister, who escapes from her imprisonment in another realm. Sound familiar?
While we're here, let's talk about Valkyrie too. Again, Tessa Thompson was great, but her Valkyrie is a wholly original creation. The original comics' Valkyrie -- a.k.a. Brunnhilde -- was, like Hela, lifted from Norse myth and, unlike Hela, also from Wagner's opera Der Ring des Nibelungen. As a result, she's got a long and tangled history with Thor. She was also an avowed feminist, a mainstay of the Defenders through the '70s and '80s, and, thanks to Amora the Enchantress and some spirit-swapping, had at least five human alter-egos -- one of whom she was also in a relationship with. Nowhere along the way was she a depressed lone-survivor of a Valkyrie massacre.
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