A foreword by the author: I've been thinking about how to fit Hela into the MCU, considering everyone is an alien and not a god there, and this is what I came up with. I hope you enjoy it.
It started many years ago, when the boys were barely of age. They were young and restless, and eager to prove themselves in battle for the first time. They heard rumors of turmoil in Nidavellir, and went with their companions to investigate. It was a grave mistake; in their eagerness and inexperience, they fought foes that greatly outnumbered them, and they were badly hurt.
But, with barely a second to spare, they were assisted by a group of Dwarfs, commanded by the young Lady Angrboda, the Second Hand of the Iron Wood Craftshop.
In the Craftshop, they were nursed back to health, albeit slowly, as is the Dwarfen medicine. Young Lady Angrboda was an intelligent woman, a skilled warrior, a better sorceress and an even better crafter, and she took great pride in cultivating her mind as she cultivated her craft. In her, Loki found friendship, and as the years passed, he found love. Then one day, she sought audience with Loki, and hours later, they came to us, to make an announcement.
They were going to be parents.
Thor was delighted. Frigga and I were concerned.
My wife and I discussed much that night, and while we agreed to keep the secret of Loki's parentage between ourselves, we decided to keep a close eye on Angrboda's pregnancy. We wanted to make sure there would be no risk in it. So we invited Angrboda to live in Asgard as Loki's rightful wife. And while they married, Lady Angrboda lived for her Craftshop, and soon she returned to Nidavellir. Loki chose to share her path, and Frigga trailed after them not longer after.
Finally the baby was born. She was a girl, small for an Asgardian but big for a Dwarf. She had Loki's black hair and green eyes, and Angrboda's curls, and not a single trace of her Jotun heritage. She was named Leah.
Half a century later, Loki came back to Asgard, refusing to speak what had gone wrong between him and Angrboda. Still, Leah came to us every year and spent months at the time in the palace. She was smart, skilled in the arts of both sorcery and sword, and the delight of the old, tired bones of my wife's and mine. Until, once when she was in Nidavellir, she changed. Angrboda ran to us, our granddaughter, her little akjellt tightly held in her arms. The left side of her little body was old, spotted and wrinkled like an old lady's, and half her hair was gray, though she seemed to be in no pain at all. And then I realized.
Leah had changed. While she would always be there, now she was Hela, fated to rule the grim realm of Helheim, the Land of the Dead.