Incubi

Incubi are a social group of hierarchal classes designated by the oneirid or a symbiote assigned to an incubus host. Is it eugenics? Perhaps.

The oneirid queen asexually produces different kinds of oneirids depending on what is needed at the time. All oneirids need a host, and the queen has a very powerful, imperialistic host, self-appointed leader of all incubi. Or is it the queen who instills these kinds of behaviours? 

The incubus and their oneirid can be very synchronized to the degree that they're essentially one being, in both body and mind. Sometimes, this doesn't succeed, and there's much internal strife.

A "raw" incubus begins life sleeping, defenseless and protected by their parents. If an incubus isn't assigned an oneirid, they'll wake up fully and never fall asleep again and lead short lifespans for this.

The oneirid allows an incubus to fall into a life-long, light dream state that allows the oneirid and incubus to interact. The incubus may also be able to exude a dream aura (a sort of type of glamour), which can help create illusions. The oneirid also allows extreme changes in the incubus's anatomy, so a very specific window of assigning the oneirid is very small, besides the host being young and still needing to grow. This is why there are so many different kinds of incubi, but there are also very uniform, predictable types as a sort of stock.

All incubi are in different states of sleep at all times. Awakening is a death sentence to them, but how one is able to induce that is a mystery since there are far easier means to kill an incubus once one gets past their dream aura.

Dream Aura

When coming in contact with an incubus's dream aura, one falls asleep (without noticing it) and is at the mercy of the incubus. Usually a dream aura extends as far as the incubus's body, but much more powerful incubi can expand it beyond their physical bodies. 

Is it possible to remove an oneirid later?

No. Usually the oneirid takes the form of an extra organ inside the host, and permanently melds into their body. Some less extreme cases may have the oneirid simply occupying the host's body and only mildly altering their physical state. Nonetheless, removing the oneirid will result in the immediate death of the host and also the slow death of the oneirid as it can't survive without a host.

Can a non-incubus have an oneirid as a symbiote?

No. The two have a exclusively mutualistic, symbiotic relationship. Trying to introduce an oneirid to, say, a human host, would end in the human's death after they fall into a deep coma-like sleep.