Board Thread:Questions and Answers/@comment-4651179-20151114011017/@comment-4651179-20151120183912

The Contest of Champions is about the Collector and Grandmaster waging this competiton for the possession of the Iso-Sphere. The Iso-Sphere is the most powerful and concentrated form of the Neutronium (aka "Iso-8").

The Neutronium is an incredibly powerful substance that changes its isometry each time there's a "cosmic renewal" (i.e. a death and rebirth of the universe), and all of these different isometries didn't allow the Neutronium to exist in regular space, until now. This eighth isometry allows the atoms to distribute in cubes, which makes the Neutronium stable outside of its place of origin, the Exo-Space (the space between realities). This eighth isometry is known as "Isometry-8" ("Iso-8" for short).

And big amounts of tis this Iso-8 form of the Neutronium exist in the remains of Battleworld. The two Elders take over the renmants of this reality and rename it Battlerealm.

While the Grandmaster takes contestants from most of the Multiverse (for example, the Silver Age Sentry and a Venom who killed Spider-Man), he can't take from Earth-616. And while the Collector can take from all of it, his consultant (Maestro), only likes to take people from one reality, Earth-616.