The Primordial Ones

"Never regret thy fall, O Icarus of the fearless flight. For the greatest tragedy of them all is never to feel the burning light."

The Primordial Ones were people who existed long ago, before the creation of the multiverse's current iteration. Many details of their life remain unknown but ancient records show that they were responsible for the creation of the Timeline Hub, as well as the original plans for the Multiverse Hub.

The reason for their disappearance remains unknown.

Canon History
Disclaimer: This section will be updated as more is revealed about the Primordial Ones.

The Primordial Ones existed long before the creation of the Hubs. They were once a highly advanced civilisation, far in the future compared to any existing universes. However, an experiment gone wrong lead to their multiverse's death and rebirth, changing the laws of reality in the process. The original universe the Primordial Ones lived in became the Hub universe and remnants of that original universe remain in the Hub universe, although they're nothing but fragments of what used to be.

Some theorise that a small number of the Primordial Ones are still alive among the current residents of the multiverse, although this is unconfirmed. It's believed that a Primordial One's power is unparalleled due to their old multiverse following different rules to the present multiverse, allowing them to perform feats which nobody from the present multiverse can, including the Creators.

Actual History
The Primordial Ones were first created on a conceptual level by Gamola during the Falling Stars arc. At the time they were merely known as Ancients and played a major role in the arc despite little being revealed about them other than their failed experiment and their involvement in the Hubs' creation.

They'd remained untouched since then until planning began for Synchóresi, at which point Gamola revamped them with their current name and a more fleshed out backstory. Their role in Synchóresi has not yet been revealed.