This universe intertwines with Genetic Earth, but focuses more on Dewey’s dimension and the human side of Earth, rather than animals.
Typically in Mirror Domain, someone will summon a demon in order to kill it. The demon is then harvested for resources (meat, bone, fur, blood, etc). Every now and then a demon will escape their summoner. The recent surge of inexperienced summoners in Mirror Domain has lead to a demon infestation.
There are three types of creatures in this world. Oomays, Demons, and Exotic Demons. Oomays are basically the “humans” of this world. Their purity ranges however. A 0% pure Oomay is basically an animal. 50% one is just on the cusp of sentience. 75-100% are the most intelligent and humanoid. In Oomay culture, your purity determines your social status. Breeding between Oomays with more than a 20% purity difference is very rare.
Demons and Exotic Demons are almost exactly the same. They’re creatures of darkness and death, that often have magical powers (this isn’t always the case). Demons are always dark in colour. Typically black, with maybe a muddy brown or purple. Exotic Demons have very flashy colours. The problem with Exotic’s is that they don’t blend in with the dark muddy colours of Dewey’s world. This means they’re easier to track down if they escape. Due to this, selective breeding has heavily shaped their abilities. They’re typically much stronger and smarter than a normal Demon, because if they aren’t they’re killed off. Demons outnumber Exotics about 5000 to 1.
In Mirror Domain, mirrors are extremely rare and valuable items. They give the user the ability to travel to different dimensions! The only drawback is that the user will turn into the appropriate form for that universe, based off their rank in the food chain in their homeworld (For example: A 80% Oomay would turn into a human. A 15% Oomay would probably turn into a dog or cat. Demons forms can range depending on a number of different factors)
This can cause a number of problems. The main one being that most creatures (that don’t travel interdimensionally on a regular basis) don’t know how to take care of their new bodies, and will often die unintentionaly.
Extra informaton: Mirror Domain overview