Episode four of Disney+'s Loki featured the unexpected return of Lady Sif, the powerful Asgardian warrior. Sif has been absent from the MCU since Thor: The Dark World, but comic fans know there is much, much more to her story. Much of it is unexpected but plays into key aspects of the Loki series.
Though a lot of Lady Sif's comic book past has been altered for the MCU, she remains a vital piece of the Asgardian corner of the Marvel Universe. With Jamie Alexander back in the role for the MCU, it's possible that the character will finally be able to explore some of her comic tales on screen.
Lady Loki Is Actually Loki In Sif's Body
The Loki series has given fans a great Lady Loki in the form of Sylvie, but comics fans know the first Lady Loki has a deep connection to Sif. In fact, Loki reincarnated his soul into Sif's body, taking it over and pushing her consciousness out into the comatose mind of an elderly woman.
This shocking event occurs in Thor #5 from 2008 and would have major ramifications for all the characters involved. Though the MCU Lady Loki is her own woman, she has her roots in Sif's story, which makes the character's return in Loki all the more interesting.
Lady Sif's Resurrection
Loki initially hid Sif's trapped consciousness from his brother Thor, stranding her in the body of Mrs. Chambers for a couple of years in the comics. In Thor #602 in 2009 (the numbering of many Marvel series oscillates between the legacy numbering going back to the beginning and the current volume) Thor succeeds in resurrecting Sif back into her original body.
The once-proud warrior struggles with her newfound freedom, though, never having suffered such a cruel and traumatic defeat as she did against Loki.
Originally Had Golden Hair
Lady Sif once had golden hair in the comics, and much like episode four of the Loki series, she lost it to Loki. In the comics, Sif loses all of her original hair to a cruel trick on Loki's part, whereas in the MCU, he cut off only some of it.
Her hair became dark in the comics when Loki replaced it with the hair of dwarves, a detail later revealed in Thor: Son of Asgard #8 from 2004. The entire episode takes a page from Norse mythology. In the classic stories that inspired all of the Marvel Comics' Asgardian tales, Loki cruelly cuts off Sif's hair.
She's Heimdall's Sister
One possible change from the comics to the MCU for Lady Sif involves her family. In the comic books, she's actually the sister of Heimdall, the all-seeing watchman of the Bi-Frost. In the MCU, the two characters haven't been shown to be specifically related.
Given the fact that Loki visits many alternate timelines in the MCU and in the comics, it's possible the show could visit one where the two characters are family. Alternatively, it could also still be revealed they are actually related in the main timeline.
In Love With Thor
One detail the MCU didn't leave behind in the comics is the fact that Lady Sif is in love with Thor. Though her feelings in the MCU are unrequited, in the comics, they have been lovers at various points.
The two have been very close since childhood, but Thor fell in love with Jane Foster while on Earth. His affection for her seemed to foreclose any possibilities with Sif, but over the years, the two would become romantic. Thor would eventually go back to Jane, though in the multiverse, things didn't always end so badly.
Sif And Thor's Son, Woden Thorson
In one alternate timeline in the Marvel multiverse, Sif and Thor married and had a son, Woden Thorson. Woden eventually grows to become a warrior like his parents and a wielder of Mjolnir.
He is born in the 31st-century timeline of the original Guardians of the Galaxy squad, some of Marvel Comics' most important time travelers. Though Woden eventually became a great warrior, his relationship with his parents was difficult thanks to Thor's constant need to be off somewhere fighting battles.
Fighting Against Loki
A major battle Sif and Thor participated in together was against Loki. In Thor #192 back in 1971, Loki seizes control of Asgard. Sif joins Thor and the Warriors Three to liberate the realm.
Loki's most audacious attempt to conqueror Asgard to date unravels when Sif confronts him in the throne room. She warns him he will have to kill her if he wants to maintain rule, and despite his constant cruelty toward her, he can't bring himself to do it. This brings about the end of his reign.
Merging With Jane Foster
Loki isn't the only character in Marvel Comics to inhabit Sif's body. Jane Foster also did in Thor #236 in 1975. The strange development comes about after Jane is injured and Sif merges her lifeforce with Jane's. In the storyline leading up to the event, Lady Sif had realized that Thor still was in love with Jane.
The merging of Jane Foster and Lady Sif would foreshadow somewhat Jane's becoming a powerful version of Thor in the comics during the Jason Aaron run from 2014. In both cases, Jane would eventually go back to being herself, though now she is a Valkyrie in the comics.
Romance With Beta Ray Bill
Thor hasn't been Sif's only love interest in the comics. For a time, she also shared a bond with Beta Ray Bill. The alien warrior worthy of Mjolnir and Sif found themselves attracted to each other over the course of the epic "Surtur War" saga, which played out in the comics between Thor #349–359.
In the story, Thor assembled all his allies and even Loki to prevent Surtur from destroying Asgard. Sif and Bill would eventually go their separate ways, but they maintained a great deal of respect and admiration for each other.
War Against King Thor
King Thor was a potential Big Bad for the Loki series at one point and remains a possibility in the MCU thanks to the early 2000s story that saw the God of Thunder turn evil. Lady Sif rose up against her former friend and lover, leading the rebellion against the increasingly imperious King Thor in a dark alternate future.
Sif plays an integral role in the story, becoming a mentor to Thor's son Magni, whose mother was the first comic book Enchantress. Sif helps Magni see the error of Thor's ways and together they undo the reign of King Thor.