You read it right; not revenants, but remnants. As in, what is left of something. Also, it'd be pronounced 'Zitharri', not Ksitharri, because the former rolls off the tongue better. It could also be abbreviated to 'The Xitharri'.

As for why I'm submitting this name, well...one doesn't just live before and after the Endless and survive without something BIG happening in the interim. This name gives Amplitude some leeway to play with a cataclysm or enlightenment of some kind in the faction's past.

Maybe they were almost killed by the Endless, so they became incorporeal to hide, or maybe they avoided total destruction because they were incorporeal in the first place. Maybe they shed their physical bodies like the Virtual Endless or they were what inspired Virtualization in the first place. Maybe they were a peace-loving, live-and-let-live faction until the Endless decided to try and kill them, so they changed into a bitter, antisocial, espionage-based society and serve as a grim reminder of how horrible the Endless could have been. Who knows?

They do.

They know everything.