Cyttorak will just negate the IG while Dormammu takes over Eternity and reconstructs the multiverse into his own image, while Sutur is left fighting Darksied, Thanos, and Superman while neither of the four of them recognizes the fact that Dormammu took control of the multiverse while Cyttorak walks away from a very small looking sphere on the ground of the extradimensional omniverse called the Multiverse.
Juggernaut already beat Magneto in several occasions.
Basically, Juggernaut's entire body and armor are not bond or made out of atoms.
An atom carries electrons, which Magneto controls. But, according to Magneto's reaction when scanning Juggernaut with his magnetic powers, Juggernaut has no atoms to control. Juggernaut and Dr. Strange explains this in various other issues that the very "molecule" that constructs the fabric of the Juggernaut is the Crimson Bands of Cyttorak.
Dante can beat Mephisto in Capcom, while inside of Mephisto's realm... It happened in Mephisto's own realm. And that realm is in Marvel which is okay, because during the Storyline (it has it's own Marvel Universe number) Marvel and Capcom merged.