Thor: Love & Thunder - 25 WTF Moments
22. Jane Has Stage-4 Cancer, Becomes Mighty Thor
The marketing for Love and Thunder was relatively coy about the means through which Jane Foster becomes Mighty Thor, and that's because, as in the comics, it's pretty heavy.
When Jane first shows up in the film, she's undergoing chemotherapy for an unspecified cancer, and given that she's in stage-4, her days are basically numbered.
Jane becomes Mighty Thor not only because Mjolnir deems her worthy when she pays a visit to New Asgard, but also because Thor made Mjolnir promise to protect Jane's life many years earlier.
We also briefly learn about Jane's own traumatic past, having lost her mother to terminal illness, and who implored her to never stop fighting.
The flip-side, though, is that as empowering as the god-like powers are for Jane - even allowing her to fire Mjolnir's shards like bullets - her time as a superhero also drains her life force and speeds up her impending demise.