Bit of a concept for a faction:

Order of Katheris:

Most demons would probably make pacts for souls and such, keeping themselves away from this now cursed mortal plane, but a few demons would rather control their subjects directly. By binding themselves to the mortal plane, they can control the functions of those they make pacts with to an extent. Through this, the demon is susceptible to the curse, but is able to act on their own wim, while only partially relying on a puppet. The demon becomes bound as an artifact of some sort, and is kept on the person of the one who the pact was made with.

These demons brought their power together under the demon Katheris, who sent many into other factions to seize power, and to help destroy Vivian and take the world for Katheris. These possessed underlings of Katheris are not easily spotted, since they do easily blend in with others.