Imaginaries

Imaginaries are a species of Kairu. They are created when someone believes in an imaginary person so strong that they become a minor deity. They don't have much power over the world like major deities but they are usually able to manipulate their form at will and go into people's minds. If they are powerful enough they can survive after their creator's death, albeit as a spirit without a physical form. In this metaphysical state they can enter people's consciousnesses and possess inorganic material.

Once they've lived outside their host for an extended period of time, they begin to create a physical form. The stronger the person believed in them the quicker they develop their physical form but the less they can change it. Imaginaries have ways to manipulate their physical bodies but the stronger the bond between creator and Imaginary, the less power they have over how they look.

This is very evident in the contrast between Irvin and Paxter Ellings and their brother Elliot Proveaux. Irvin and Paxter were believed in very strongly by Ren and, beside from the wear-and-tear of physical bodies over time, have little power over their appearance but gained a physical form in less than ten years. On the contrary, Elliot was created far later than Irvin and Paxter and not believed in as thoroughly. Due to this, he hasd't developed a physical form for over 180 years and instead possessed a Reni steam automata.