Demons

Demons are an ancient race of unknown origins, known for their resilience and connection to dark magic. They, at their core, exist in a spectral form and create a physical "shell" for themselves to interact with the world.

Biology
Demons seem to follow a sort of hierarchy within the species. Demon Kings or Demon Lords. are at the very top of the hierarchy, usually ruling over a group of demons. Arch-Demons are the second highest, usually being physically stronger than regular demons. Then there are Pureblood Demons, demons who have no little to no genetic relation to other species, though are weaker than Arch-Demons. Second lowest are the DemiDemons, also known as Half-Demons. Created when a demon breeds with some other species, and finally Demon Adjacents. Demon Adjacents are a phenomenon caused by interspecies breeding. Although some interspecies children become DemiDemons, most become Demon Adjacents. These creatures are pale, weak, and usually don't survive their first year of living. They are completely sterile and cannot breed. Very few make it to adulthood, as most parents will abandon them, but if raised in good enough conditions, a Demon Adjacent can learn to thrive.

Demons feed on negative emotions such as sadness, anger and fear among others to nourish their spectral form. These emotions will release a sort of spectral energy. Demon skin is coated in a fine, nearly invisible dust that will attract this negative energy towards it. The energy then is absorbed through the skin and consumed to sustain the demon's spiritual form. This however, doesn't mean a demon doesn't need to eat. They require food to sustain their physical form as well. Demons will 'hunt' for these negative emotions by creating grief, desolation and performing other nefarious actions. This has earned them nicknames such as "Embodiments of Sin", "Bringers of Evil" and "Massive Assholes". In a pinch, a demon can use their physical nourishment (regular food) to sustain their spirit, or vice versa, though only in a pinch. Malfunctions in this process are the cause of the 'Demon Adjacent' phenomenon. Usually, a hybrid won't inherit the genes to intake and process negative emotions, or they can only intake and process negative emotions and can't process physical food. The latter will lead to a death before they're even born. The prior however, can still survive by using physical food as spiritual nourishment. This means they require twice the food intake, and are usually too physically malnourished to survive very long.

Culture
There is no one demon culture due to demons being more or less scattered across the land, but there are some legends passed around a few groups. In some of these legends, demonkind originated from "The 5 original Arch demons". None of this has much evidence to back it up, so it doesn't have much historical merit. Some think that Lukas Lordinger was the first original Arch-Demon that got conjured into Rathnir. Demons tend to accept certain cultures, but don't follow many religions. The reason for this is unclear. Demons get normally conjured in an age between 1000 and 5000 years, As the older one is, higher their ranking.