|The Imperfect Triangle Multiverse|
When we started doing the multiverse thing in our Scrap Pile adventures (ICONS superheroes), one of my characters was Professor Hemm. He was created to help solve all the dimensional wall issues that Peryton was throwing at us. We kept spilling into the 80s Universe where Mister Roboto by Styx was the reality. Dimension Q the domain of the dread lord Kithraq was spilling into our own. Baron Karza from the Micronauts, the Marvel one, was worked in there as well. So in one game session the "Imperfect Triangle" of our Scrapverse realities came into being, so we could conclude the over-arching dilemma.
Along three reality poles, Myth, Mechanical, and Mayhem worlds are set. Hemm was able to identify the ties of each of the universes to the respective centers of extremes. Creating, well actually embodying forces already in existence if amorphous, the "Tether Guards" Psy and Psi would reinforce the dimensional barriers by maintaining the singular worlds anchors to their poles. Of course there had to be a big superhero battle in Avengers movie tradition to get things stable.