Jane Foster, played by Natalie Portman, was first introduced to the MCU as Thor’s love interest. Initially, she just stumbled into the world of Norse gods before then playing a more active role in Thor: The Dark World, discovering the Convergence of the Nine Realms. In the sequel, Foster comes into contact with Aether, which slowly starts to infest her body and almost kills her. She survives the ordeal and even gets to visit Asgard with Thor, but that was thought to be the end of her story, as Portman left the MCU.
She was reportedly unhappy with Marvel’s creative approach and how they treated Patty Jenkins, who was supposed to direct Thor: The Dark World. But after Marvel Studios’ course correction and corporate restructuring in 2015, they seemed to have patched things up with Portman because she’s back. Additionally, with the franchise being reinvigorated under Taiki Waiti’s direction, the character of Foster is also undergoing an evolution. She won’t just be a romantic cliché in Thor: Love and Thunder, she’ll be wielding Mjolnir herself. Which apparently came as a surprise to the actress as well.
But whether Foster will be the Mighty Thor for multiple films before joining the Avengers or walk a totally different path is still unknown. One theory, however, suggests that this could be a transitory phase, leading to her becoming a Valkyrie.
The comic books have put Foster through a similar transformative journey. When Thor believes himself to be unworthy, Foster wields Mjolnir, becoming the new Goddess of Thunder. But there’s a catch, as she’s suffering from cancer and undergoing chemotherapy. Every time she transforms into the Mjolnir-wielding superheroine, though, the effects of her treatment get negated. But she understands the importance of Thor’s role in defense of the Nine Realms and continues using the enchanted hammer and this sacrifice deems her worthy enough to lift the weapon.
In the heart-wrenching conclusion, Foster transforms one last time to go up against the beastly Mangog. But the battle costs her both Mjolnir and her life. Give that this is Marvel Comics we’re talking about, though, characters don’t always die for good. Odin is moved by her heroism and manages to resurrect her and Foster resumes her life as a human and continues to undergo treatment. It’s unlikely that Waititi will use the same plot device, but the story might follow a similar pattern, with Portman’s role changing from Mighty Thor to Valkyrie.
The evolution of Foster’s story is part of the ongoing comic book series Valkyrie: Jane Foster, which explores her role as the new Valkyrie after the original battalion is slaughtered in the War of the Realms event. Some threads from the movie and comics are already running in parallel, too. Except for Tessa Thompson’s character, all the Valkyries have been wiped out by Hela, as we saw in Thor: Ragnarok. So, the MCU could very well introduce a new squad of Valkyries starting with Jane Foster in Thor: Love and Thunder.