Multiverse Unlimited

The multiverse - A series of parallel universes, dimensions and realities all separated by an intangible force; a dimensional wall that keeps each world on its own side. Under normal circumstances inhabitants from these worlds crossing over into other worlds was extremely rare; and even then the scope of worlds they could cross into were very limited. However, in recent times it has become increasingly more common, with inhabitants from across the multiverse coming together as a whole.

Scientists and the general population are baffled as to how and why this could be possible, and the truth of the matter is something that only a select handful are privy:

Harnessing and merging the powers of technology and supernatural forces, a brilliant scientist by the name of Dormus Dullahan invented a complex networking system known as the Aethernet. Using this system he discovered he had the means to open portals in the space/time continuum and effectively move objects and life form from one world to another. However, while attempting to free a chaos deity from its confines, imprisoned within a pocket dimension, the Aethernet malfunctioned. It began operating out of control, opening gateways throughout the various dimensions and allowing inter-connectivity between worlds which formerly had no rational means of contact. And thus began what would later be dubbed Multiverse Unlimited, or 'Mu' (pronounced 'mew').