Warning! Spoilers for Thor #20 by Marvel Comics
With Thor losing control of Mjolnir and his trusted hammer ravaging the Ten Realms, the being behind the God of Hammers prophecy is revealed: it's the living embodiment of Mjolnir. In a shocking Marvel Comics reveal that's one for the history books, Thor came face face-to-face with the God of Hammers and finds his trusted weapon wielded by the living embodiment of Mjolnir - who has its own thunderous form.
Thor's connection to Mjolnir has recently weakened as it's become unpredictable and heavy, with even those who are not worthy being able to lift it. A bad situation turned worse when Mjolnir was stolen after Thor left it with the Avengers. Nevertheless, Thor searches for answers as the prophecy of the "God of Hammers," foretelling the King of Asgard's death, seems to be underway. While seeking help on Nidavellir, home of the dwarves who crafted Mjolnir, he finds nothing but death and destruction caused by his hammer.
In Thor #20 by Donny Cates, Nic Klein, Matt Wilson, and VC's Joe Sabino, Thor not only finds the dwarves of Nidavellir slain by his hammer but discovers the Frost Giants on Jotunheim have also been murdered by Mjolnir. As Odin tries to dismiss the God of Thunder prophecy as a myth, Loki tells Thor it's very real. With records of the prophecy recently destroyed, Loki learns it starts with The God of Hammers rising, igniting the Ten Realms, becoming the King of Asgard, and then reshaping the world in their image. Lady Sif arrives and takes Thor to a ravaged Broxton, Oklahoma, the former home of Asgard on Earth. As Thor cries out, Mjolnir attacks. When it lands, the living embodiment of Mjolnir reveals itself as the God of Hammers.
The God of Hammers being a thunderous form of Mjolnir is one of the more surprising twists in Marvel Comics history. Is this a sentient version of Mjolnir? Perhaps the God Tempest, the mother of all storms, has been freed from Mjolnir and is ready to get revenge on Odin for trapping her inside the hammer?
The God of Hammers went out of their way to erase themselves from the history books, but if the prophecy is true and it wants to destroy the Ten Realms so it can rule Asgard, Thor is in more trouble than previously believed. The God of Hammers has arrived, and right now, nobody, Thor included, can stop the thunderous living embodiment of Mjolnir. Thor #20 is in comic book stores now.