In a moment of wistful affection for his girlfriend, Thor asked his trusty hammer to always protect
However, the film also implies that the hammer only sees Jane as worthy because Thor unintentionally revised the rules of Mjölnir, giving it the power to protect her. Captain America didn't need anything special for the hammer to see him as worthy – he's able to wield it without issue in Avengers: Endgame.
Thor: Love and Thunder put into question whether Thor is still worthy because rather than coming back for Thor, Mjolnir magically reformed to save Jane from her terminal cancer.
Mjolnir fixes itself in Thor: Love and Thunder because of Jane's illness. Thor loved Jane so much while they were together, the hammer developed a kinship for her, and wants to protect her at all costs. When Jane visits its shattered pieces, they react to her terminal cancer so strongly that the hammer rebuilds itself.
But in the new film, Thor: Love and Thunder, Mjölnir is back, and, like a fickle pet has chosen a different owner: Thor's ex-girlfriend, scientist Jane Foster. Indeed, the hammer calls to Jane (Natalie Portman), who is undergoing chemotherapy to treat Stage 4 cancer.
Is Thor still worthy in Thor: Love and Thunder? It is pretty clear that Mjolnir chose Jane, not because Thor was unworthy, but because Thor's oath had instructed it do so. Sadly, the hammer cannot cure Jane's cancer, and can only transform and temporarily empower her.
In the film, Mjolnir “chooses” Jane not because of her own worthiness, but because of what we see in a flashback to when she and Thor were still a happy couple.
One possibility is the simplest one available, which would hinge on the rules put on the hammer by Odin's enchantment, which are “Whoever holds this hammer, if he be worthy, shall possess the power of Thor.” Jane was able to take Thor's place in the comics because she became worthy enough to wield Mjolnir, so if the ...
With his Infinity Formula that had kept him from aging failing him, Fury was severely weakened but able to incapacitate Thor by whispering something in his ear that immediately made him unable to lift Mjolnir; the Odinson rendered unworthy in an instant.
This led Jane to New Asgard, where the broken pieces of Mjolnir were held. Up until this point, no one had used Mjolnir — not even Thor, who likely believed that nothing could put the destroyed hammer back together. Jane's arrival in New Asgard woke up Mjolnir, allowing it to reform to transform Jane into Mighty Thor.
Thor became unworthy in Original Sin, but it wasn't until The Unworthy Thor when we learned why – and it was very different from the movies. Thor has become unworthy of using the Mjolnir in both the Marvel Cinematic Universe and Marvel Comics, but for very different reasons.
The broken pieces were eventually made into a tourist attraction in New Asgard. Five years after the Snap, Thor time traveled to an alternate 2013 and brought its Mjølnir into the main universe's 2023, where it was used by Steve Rogers during the battle to fight an alternate Thanos.
Tony Stark was not able to lift Mjolnir because he did not meet Odin's standard of worthiness, which obviously is not based on self-sacrifice alone. After all, he placed the worthiness enchantment on the hammer to teach Thor a lesson about the failings he needed to overcome come before he could become king of Asgard.
The two brothers, clouded by pride and hate, send the Destroyer after Jane, despite the new Thor saving others and fighting for what's right. While she gets thrown around, Thor refuses to back down, which is another reason why Jane is worthy of being Thor.
While Thor made Mjolnir promise to always protect Jane, this likely wasn't the only reason why she could wield the hammer.
It is revealed that Thor and Jane broke up sometime after the events of Avengers: Age of Ultron. When a fangirl tells Thor she's sorry that Jane dumped him, he sheepishly replies that it was a mutual breakup.
In The Unworthy Thor #5, which released in comic shops today, the words Nick Fury said were finally revealed. "Gorr was right." Three simple words that undid the God of Thunder.
Gorr planted seeds of doubt in Thor's mind, forcing him to question whether gods truly are as noble and benevolent as they seem. Nick Fury seizes on that doubt in 2014's Original Sin, telling Thor "Gorr was right" and rendering the god of thunder so disillusioned that he's no longer able to lift Mjolnir.
Following his defeat, Thor began to refer to himself as merely Odinson, wallowing in his loss and humiliation. It wasn't until 2016's Unworthy Thor #5, by Jason Aaron, Olivier Coipel, Kim Jacinto and Pascal Alixe, that Thor finally revealed that the words Fury had said to him were simply, "Gorr was right."
Jane does not transform into a god-like being like Thor himself. While she does get to wield his powers while in her Mighty Thor form, she is not permanently altered. Instead, she returns to her weakened human form once she lets go of the hammer.
Odin placed several enchantments upon Mjolnir prior to Thor wielding the hammer: This is reflected in the inscription on the side of Mjolnir, which states: Whosoever holds this hammer, if he be worthy, shall possess the power of Thor. For almost the entirety of Marvel continuity, this has exclusively been Thor.
Mysteriously, the broken pieces of Mjolnir, the hammer of the thunder god, transformed her into the Mighty Thor and gifted her the superpowers of Thor, to battle threats internal and external. Wielding Mjolnir herself, she had become a godly protector and a new hero was born!
If fans wait to see Peter Parker lift and use it in MCU, they may be disappointed. Despite his strong moral sensibility and strength of character, Peter lacks the ruthlessness that destroys all evil. For this slight defect in character, Mjolnir will never find this Spider-Man worthy of it.
Is Spider-Man worthy enough to lift Mjolnir. The short answer is yes, Spider-Man is able to lift Mjolnir but it's not that simple. While Spider-Man can lift Mjolnir, Peter Parker cannot. That's because it's Miguel O'Hara's Spider-Man 2099 that can lift Mjolnir as he does in 1998's 2099: Manifest Destiny one-shot.
The catchphrase actually has some precedence in the comics, and the answer to what Jane whispers to Thor may come from the same source. In Mighty Thor Vol 3 19, she says "You wanna eat my hammer, lady? Then by all means... take a big bite!" That tone fits the way Jane and Thor laugh, at the very least.