The Domain of The Gods.
No one truly knows when it was made, or how the civilizations inside it came to be, or how anything truly worked in it. The only thing its residents truly know is that each of them that were living there was capable of doing damage at the apocalyptic level — that was the very reason they implemented their own rules in the first place.
If there was one god who happened to become violent, the damage he would do would probably become like dominoes, just rippling across the domain and affecting the other gods who have learned to suppress their violent urges.
There was nothing to do in the Domain of the Gods at the start, it was more like a prison to keep godly beings. There was nothing to do, nothing at all except one.
The search for a Cosmic Piece.
This is, in no way, a reference to One Piece.