Thor stories have always been home to some of Marvel’s finest weirdness. There are of course flying goats and rainbow bridges, as well as Frog Thor and Beta-Ray Bill, but those are the big, obvious things. Sometimes the oddities of Thor become instant classics. Other times, however, they simply stand out as strange moments that are quickly forgotten. The latter is the case for Marvel’s brief replacement of Thor with an entirely different God of Thunder in 2012’s Mighty Thor.
Written by Matt Fraction, Mighty Thor #8 takes place after everyone’s favorite Norse myth has fallen in his battle against the Serpent Cul Borson. His allies build him a funeral pyre and as the flame consumes the body of the fallen Avenger, those gathered to pay their respects see something in the flames: The form of a man — no, a warrior. Out steps Tanarus, God of Thunder, Champion of Asgard and one of Earth’s mightiest heroes. While all Tanarus’s allies cheer the return of their fallen friend, Loki is reserved.
This isn’t simply because of his long-standing rivalry with his brother, but because he alone is able to tell that this is not his brother. In fact, only he even seems to remember that there ever was someone named ‘Thor’ at all and that this so-called hero standing in front of them now is, in fact, Thor’s old foe Ulik the Troll.
Under a devious enchantment placed by Karnilla, Ulik usurps Thor not only as the God of Thunder but in the minds of his allies as well. The spell makes it so that everyone — except Loki and Heimdal — believes there has only ever been Tanarus and every memory of Thor has been replaced with Tanarus. Ulik isn’t simply doing this for glory, or out of jealousy of Thor; it’s all part of a plot to plunge Asgard into chaos to weaken it for an upcoming troll attack. At this point, Odin is out of commission and Freya has ascended to the All-Mother. It is Ulik’s mission to use his new status to get close enough to her so that when the time is right, he can assassinate Asgard’s ruler before his fiendish allies attack.
While he appears to be the champion of Asgard and is remembered as such, he is still only Ulik in disguise and his troll-like behavior generates disgust among the Asgardians. Heimdal begins to suspect something is amiss about the realm’s champion and when he realizes he’s unable to see Tanarus, he knows something must be deeply wrong. He confronts the disguised troll while Ulik is shoveling food into his mouth and trying to put the moves on Sif. The two clash, but Ulik is too strong for the guardian of the Bi-Frost and defeats Heimdal. However, he is not deterred and Heimdal manages to stop Ulik before he can strike down the All-Mother.
While all of Asgard is going to Hell in a handbasket and the trolls are mounting their attack, Thor is in the middle of it, fighting his way out of the stomach of the Demegorge. Much like in both Ragnarok and Endgame, he returns to Asgardia with a dramatic, final-hour thunderstorm. The whole story is weird and a little off-putting, but there is something so satisfying about watching a battle-mad Thor arrive to put the hurt on some villains. As soon as he arrives, Karnilla’s spell is lifted and everyone remembers him. Thor obliterates Ulik; literally, there is nothing left of him except for his spine and skull, which are used as a magical prison for Karnilla and Geirrodur.
Just like that, the Thunder God Tanarus is forgotten by the Asgardians and Marvel readers alike. Whatever Marvel decides to do with Thor when Chris Hemsworth’s contract is up, you can bet it probably won’t be Tanarus.
In Mighty Thor, the titular God of Thunder was replaced with a villain. Here's a breakdown of what happened.