Multiverse creation takes a long while, a lot of fine-tuning, and a lot of stuff that gets thrown out and put in too, it's a difficult job creating something out of nothing. But with every multiverse, comes it's byproducts.
Artifacts. Maybe you've seen them? Maybe you haven't. These entities accompany the multiverse hub, but seeing them in the centre of everything is a rare sight, the Otherworld were lucky as they were right in the middle of the multiverse hub, yet were never spotted, or were kept alive just to see what would happen.
They can be everything, everywhere. There can be an artifact lost in a void, an artifact that's in the multiverses, an artifact in the centre of the hub, or it could be a friend you know. You'll never know, only they do.
Rumour has it, the artifacts have one ability, one they all share, whether they know how to use it for good, for bad, or not at all.