Derived from the aes sidhe and the baan sidhe (pronounced and better known as the banshee), this name is meant to call to mind the same Irish ghost stories. It is intended as a proper cultural name rather than the nicknames some factions have, something the faction would call themselves in their own language rather than a title they would receive from others in the galaxy.

This could be interpreted various ways for faction lore, such as by giving the Cen Shay their own tradition of ghost stories, assuming they are ghost-like aliens and not true undead, as well as the possibility of a historical or mythological bent to their logic, derived from the way they have observed history over the centuries since the Endless existed, turning the idea of historians uncovering curses and ghosts on its head by having ghostly historians.

I like your idea.

Whether or not this name wins, I want it to be what the faction themselves use! (Maybe have a name more familiar to outsiders)