The universe of Heroes Assemble MU* integrates major thematic concepts from both the Marvel and DC universes. The arrangement and hierarchy of powers in those two universes tend to be radically divergent and required some explanation to reconcile. Here are some notes to help you better understand how some of these concepts are arranged. Anyone familiar with Neil Gaiman's 'Sandman' series will see familiar concepts but we have taken great pains to integrate Marvel's concepts as well.
Multiversal Entities: Some entities are so potent that they straddle the entirety of the Multiverse. The architect of Creation is the Presence. Entities such as Perpetua and the Monitors, as well as the Heavenly Host, are tasked with maintenance and creation of the multiverse itself. Second only to the Presence are the Archangels Michael and Lucifer. These entities are sufficiently vast that their consciousness and awareness can span multiple universes simultaneously with no ill-effect.
Major Powers: The Major Powers are entities that are akin to fundamental forces for each universe that exists. We have coined the term ideologue to explain these entities/awarenesses. They are an intersection of both intelligent and metaphysical intent. Examples of these entities are the Endless, the Phoenix Force, the Speed Force, and the Eternals. They belong to the category of First Gods or Elder Gods. The destruction of the First Firmament led to the creation of the Multiverse as we know it now.
Lesser Powers: The 'Godwave' did not occur in our canon as described in the comics. The creation of the gods of human myth, such as the Olympians and Asgardians, occurred approximately 50,000 BCE. The universe is littered with 'pocket dimensions' called demesnes that serve as the residence for these entities. The area around Earth is particularly rich with these locales due to the presence of the Demiurge. The entities are all collectively regarded as the New Gods.
Fundamental Realms: The larger multiverse is divided into several different regions. Nullspace is the term we've coined to represent the Anti-Matter Universe, the Dark Dimension, and the Phantom Zone. The Astral Plane features heavily for mystics and dreamers. Hell is quite real, but many entities are pretenders to the throne or even lords of a false echo of that realm.