How Jane Foster Becomes Thor

While Jane Foster was now known as Thor and was carrying Mjolnir around to crack skulls and save the day, this all came at a terrifying price for Jane.

Still suffering from breast cancer, Jane becomes Thor by reaching out to Mjolnir. The thing is, each time she does this, her body is cleansed of all the chemotherapy treatment. Every time she becomes Thor, she does so with the knowledge that her time as Jane is coming to an end.

By the time of 2018's ominously titled The Death of the Mighty Thor story, Jane's cancer had reached the level where she would die if she transformed to Thor one more time. Despite her fellow Avengers warning her against doing so, and despite Doctor Strange even confirming that she would die, Jane decides to sacrifice herself in order to protect Asgard from Mangog.

With Asgard and every single Asgardian facing death at the hands of the Mangog, Thor manages to overcome the odds and attach Mjolnir to Mangog in order to fire him into the sun. Thor has saved the day, but with Odinson at her side, the loss of Mjolnir causes Thor to revert back to her terminally ill human state.

Sharing one last kiss, Jane dies in Thor's arms - and the room got a little dusty for every single person reading the pages of The Mighty Thor #705 back in March 2018.

As Jane stands at the gates of Valhalla, the combined efforts of Odinson and Odin would miraculously bring her back to life. From there, Jane handed the Thor mantle back to Odinson while she focused on her chemotherapy. And not just that, but post-recovery Jane would end up becoming a warrior of the Valkyrie.