"The Utukku" (from Sumerian mythology - incorporeal spirits that had escaped the underworld by their own guile or by being summoned)

The Utukku were of ambiguous disposition, they could be benevolent or malicious. The "good" Utukku were called Lamassu, the "evil" were called Edimmu. I see this as a good opportunity for a part of the faction quest, where they decide how they want to interact with the other civilizations (similar to the UE quest where the player picks between Sheredyn, Mezari, or staying as UE). 

Utukku were thought to be responsible for spreading disease and possessing the living, but could also be responsible for silently protecting individuals and shadowing them wherever they went. All of these characteristics fit nicely with what (little) we know about the faction: ancient, alien, wraith-like, and taking on a incorporeal and shadowy form.

I don't like the phonology (how it sounds) or aesthetic of this word at all but the meaning is far too good to pass up on, and it brings with it the concept of two rival houses with different approaches to espionage, so I am on board.

Love it, was thinking something similar but I figured I should check the list! (I would have simply starting with Edimmu but I like your idea better anyway!)

Nice idea. The dichotomy here is welcomed and would inherently bring the 'good or evil' option to the player.

I like the way the name sounds too - very alien. I'm not sure I'm hearing ancient, but cool none-the-less

What i like most about this, is it takes inspiration from a truly ancient language (sumerian). Would like to see more like this, it better make it to the finals!