Phantom Breaker: Battle Grounds-1R
At a glance, this world is a modern Earth variant. The year and date is the same as in the OOC real world. But under that, the multiverse theory is in full swing; an infinite amount of parallel Earths exist (most very similar and being different in only one detail, like a specific character doing or not doing a specific thing and thus changing the timeline). An entity called Phantom travels between these Earths, offering to a number of wanting people powers and a weapon called a Fu-mantion Artifact.
Owners of Fu-mantion Artifacts, or F.A., are tasked to fight each other until only one is left. To those people, Phantom will grant a wish, whatever it may be.
Though Phantom is honest, his ability to grant a wish in any given reality depends entirely on one thing: the barrier between dimensions must be weakened by F.A. wielders first. With every swing of their weapon, these people break reality, until Phantom is able to enter that world with his full power and add it to his dominion, while also granting the winner's wish as promised (a wish determined before he reveals the effects his arrival has).
It is in one particular iteration of Tokyo that numerous people gather for the latest competition set up by Phantom. People with a wish, people trying to stop him, and people from other worlds-- allies and foes alike, with some trying to stop Phantom from consuming yet another world, but others, prior winners, there to help him.