The Norse God of Thunder Thor was among the most central figures of the grand re-imagining of Marvel that was the Ultimate Universe, and while Ultimate Thor's origins and life initially mirrored Thor of the main 616 Marvel Universe, his journey would eventually diverge down a grim, bleaker path. True to the Ultimate continuity's core mantra, the status quo for the thunder god would be irrevocably broken. From the ashes of unfathomable loss, this Thor would gain a darker superpower beyond any other wielded by the Son of Odin.
The Ultimate Universe was founded on the idea that the world had consequences. The inexorable "status quo" that plagues mainstream comics wouldn't be present there - the dead stayed dead, heroes who fell to villainy would not have their sins easily absolved, time marched forward and people grew old. Even the very gods of Asgard, a realm defined by an eternal cycle of destruction and rebirth, were not immune. In a singular fell swoop, the gods would find themselves cast down - only this time, there would be no resurrections. As a result, Thor would become a living vessel for the Norse afterlife, Valhalla.
Reed Richards Wipes Asgard Off the Map
Ultimate Comics Ultimates (2011) by Jonathan Hickman and Esad Ribić is something of a decade-long culmination of events. The Maker, secretly a now-villainous Reed Richards, creates the Children of Tomorrow. Inside the Dome, the Children experience a vastly accelerated 900 years of progress towards Richards' vision for the world - a technologically advanced, collectivist race of genetically perfect superhumans. One of the Children's first objectives is to identify and eliminate the few potential threats that would prevent them from establishing global dominion.
First among these is Asgard, home of the Thor and his fellow Norse gods. The Maker and his Children launch a preemptive strike, resulting in a battle more akin to a slaughter. The gods "fell like rain from the sky" as the Children butcher them and put the World Tree, Yggdrasil, to the torch. Every Asgardian and all connection to the realm of the gods is forever extinguished by the Maker's attack, save one: Thor Odinsson. While he is the last survivor of Asgard, Thor is not alone. As the very last of what was Asgard, Thor becomes Valhalla itself, with the spirits of countless fallen warriors now eternally bound to the god of thunder.
Thor Becomes the Living Hall of the Dead
Asgard existed in a cycle of eternal destruction and rebirth known as Ragnarök. While Ragnarök is often viewed as Norse mythology's Armageddon, this is only half true. While Ragnarök does bring about the destruction from Asgard and the deaths of most the gods, from the ashes Asgard and its gods are reborn and the cycle continues. The Maker's attack on Asgard breaks the wheel. As Thor feared, it is worse than Ragnarök - the end of myth, the end of gods. As the last surviving vestige of Asgard, Thor now carries Valhalla with him. He is forever surrounded, haunted by the countless worthy dead throughout the millennia including his own friends and family he failed to save. While Thor may draw some comfort in always having his father and brothers at his side, he is cursed to spend the rest of his life staring at the faces of those he's lost. And, should Thor perish, there will be no Valhalla awaiting. With no other piece of Asgard to attach itself to, Valhalla would fade into the ether. Eternal feasting with his fallen friends and family may not await Thor when he es, only oblivion.
Becoming a living embodiment of Valhalla is a jaw-dropping power, but the price Thor pays for it is steep. Only the complete destruction of his home and extinction of his race makes it possible, and for the thunder god the price is inescapable. The ghosts of the fallen will always remain at Thor's side, a grim reminder of all that he has lost.