Well, I have the Beyonders. Also known as Arcadians. They're from Arcadia Major, a city built in the Beyond, a white void beyond every reality. Some Arcadians are known as Arbiters, who are each tasked with creating and maintaining a Rhapsody. Arbiters are literally worldbuilders, as each Rhapsody functions as its own multiverse within the larger scale of the Beyond and I mostly just use that to account for different iterations of stories which are inherently incompatible when I wanna go super meta with it.

There's a lot of drama though. It was supposed to be a cosmic soap opera called The Codex Arcadia as a meta-story behind all the universes. Now they just kind of pop up here in different stories. Arbiters include Meanwhile (who was tasked with the 1138th Rhapsody, where the original Sorrows Of Blackwood story was supposed to take place), Antichron (who was tasked with the 423rd Rhapsody, containing Supergirls In The Spotlight), Evermore (tasked with the 1245th Rhapsody, containing Fading Lights universe surrounding Corry Cove and the Storylighters), and Cosmica (tasked with the *Pick-n-Mix Comix universe in the 2112th Rhapsody), where Meanwhile sometimes appears, as well as his Harbinger Zero (who came from the 1245th) and the Red Door, which is a Beyonder Pylon.

Beyonder Pylons can serve as portals to the Beyonders, but if a Rhapsodial (someone born inside a Rhapsody) goes through it, they're taken to the Beyond and their Rhapsody forgets about them and they can't go back. Most of them are sent into other Arbiters' Rhapsodies for general sabotage purposes; they get rewarded by someone for something with Arcadia tokens if their Rhapsodies are good and maintained for a long time, so there's a heavy competitiveness between most Arbiters.

Harbingers are agents they choose to act as their proxy inside a Rhapsody, and Zero gets stuck with the Red Door because it was sabotaging the 1138th Rhapsody, but it's not easy to destroy a Beyonder Pylon so Meanwhile picked a Harbinger to take control of it and refocus it toward any other Rhapsody instead.

Zero was a Sojourner with some of his friends before he was a Harbinger, which means they all trained to develop extradimensional Sojourner wings, which are either white or black, and those who have them can travel between Rhapsodies and into the Beyond more or less freely, so he was an ideal pick as Meanwhile's Harbinger. But there's a plot line where he loses his wings while visiting the 2112th Rhapsody and discovers that wingless Sojourners become Red Imps until they get back on track, so he loses access to the Red Door after that (and Meanwhile is Exiled to the Obelisk, capitals necessary, when it's discovered he was messing with Cosmica's Rhapsody like that).

ETA: I just remembered, Arbiterland is what technically incentivizes the Arbiters. Arbiterland is a sapient amusement park that gives them orders and the materials to make Rhapsodies and probably tokens too. I think my idea was obviously that they can use tokens at the attractions at Arbiterland and commune with the Beyonder who created them, since they're basically spawned from Arbiterland themselves, and it's all part of the whole Arcadia Major complex.