Tom DeFalco has some works around the multiverse in Thor's comics, even with higher dimensions. He is the author of both Seth sagas, which takes place during Thor vol 1, and the Seth saga that takes place during the Journey into Mystery, before Thor vol 2. Basically, in the classic ones, we have these two comics just to develop the idea of Yggdrasil.
First of all, I am not here to discuss what is believed, or accepted, to be the higher dimensions here, as mentions of dimensions infinitely higher than the other, it has nothing to do with the idea of multi-dimensional state, and in the current system, There is not even a need for such infinity mentions, although Marvel works on such systems, as has been shown in some cases in classic and current comics. (But entering them would detract from the purpose of my comment here.)
Tom's main work on Thor's comics was in the Seth saga, and I will also explain very simply why Seth, Odin, and Surtur doesn't scale to the feats within this saga.
If we take how Tom DeFalco worked with the notion of "planes" on Thor's comics, we will see in Thor # 402 that he uses the idea of higher and lower spatial levels,
we can see when Asgard is mentioned moving between the higher planes of reality, to the lower planes of reality . Showing that Tom DeFalco's cosmology had "higher and lower worlds" in its planes of existence.
The statements to the idea of Yggdrasil being established as a Multiverse comes from both sagas, the first Saga Seth, is in the
idea of planes as the entire multiverse .
The second mention is in the Journey into Mystery, a dangerous mention that, if not well contextualized, can generate an upgrade for Odin and Seth when taken out of the context of the story, in this comic,
Doctor Stranger treats Yggdrasil, or at least, the fight for Yggdrasil as a threat to the whole multiverse (The fabric of the multiverse itself is at risk according to him) , and this fight for Yggdrasil echoed through all planes of existence.
In fact this feat is amazing for both Odin and Seth, but the point is: They don't scale to this at all, there's a reason they were able to affect these planes of existence. But first of all, in the Seth Saga, it is determined that Yggdrasil is more powerful than Odin and all Nordic gods combined, Yggdrasil could take away all of their powers simply by not believing they were alive anymore. And Odin is reinforced as more powerful than Seth, even Seth in his prime. Therefore, Yggdrasil> Odin> Seth
The explanation for why the planes for existence were affected form them comes from what Seth did during the Journey into Mystery, Seth mentions that he weakened Yggdrasil, so there's a whole context for why
Yggdrasil was weaker/more vulnerable , the walls between the planes had been weakened, which is why Seth was able to affect Yggdrasil at this point.
Therefore, from what is presented in the Journey into Mystery Saga, neither Seth nor Odin could do that with all planes of existence under normal conditions where Yggdrasil was not "weakened."
About TWSAIS, the fact that they could have been created by the Norse Gods has nothing to do with their level of power, that is because this logic is so unreal, the Norse gods were created by the minds of humans, and fed on their energy. (See Thor's Annual on the origin of the gods, and Gaia's mentions of what the power of the gods is)
But still, Odin is a force always represented as being beyond human reach, in every way, the same can be said about Surtur and other Nordic beings as well. I am just commenting on this to show even more the lack of logic in this argument.
And please, although Loki is currently the god of stories, during "Loki: Agent of Asgard", it has been shown that even his form within the multiverse is only a self-projection of himself, where he remains narrating his story from outside.
If anyone here wants to discuss the consistency of Thor's story, the different representations, or the cosmology used for Marvel about the "Myths" (Which would be much better developed on a blog, perhaps, to stay on Marvel's own page (I don't know if it can, but it's interesting), it would be great.
Tom DeFalco has worked in various sagas about Thor and The Multiverse, another saga where Tom DeFalco showed the gods beyond the classic "9 realms" was Thunderstrike,
where the clash between Mephisto and Hela is classified as a threat to the multiverse , far greater than the threat to the "9 realm" that the story of the Norse would represent.
In this same saga we
also have the idea that Odin could be higher than that ,
where Mephisto classifies him as an "equivalent power of his ow ."
I'm not saying that Odin should be "High 1-B" or anything like that, but he also needs an upgrade, he and Hela clearly scales to beings like Mephisto, Dormammu, Nightmare, these are characters very present in classic comics with 1-C power.
