Mamono Realm

The Demon Realm is an area that has been saturated in the demonic energy of the Monster Lord and is therefore only habitable by Mamono and the servants of the Monster Lord.

History
What the demon realm was like before the current demon lord rose to power is unknown. Afterward, however, it became heavily influenced by the lewd demonic powers that coarse through the current Demon Lord’s body. This resulted in an environment in which just about everything revolved around sex.

Due to the actions of various Mamono, the demon realm has expanded past its original borders. In some cases, these new areas aren't even physically connected to the original, due to the Mamono responsible for creating the new demon realms being too far from the original for the new realm to connect with it.

Culture
Although the demon realm, in which lust runs rampant, may give a first impression of having no order, this is not entirely true. Aside from the demon lord, who rules over the demon realm, along with her Lilim daughters, who are known to fill the roles of princesses, there are indications of social status among the Mamono. The widespread example of this is the large amount of respect directed towards succubus who, having specialized in sexual techniques long before the current demon lord’s time, are known to wield greater power and abilities than the average Mamono. Another example of this would be the vampires and their husbands, whom are viewed as nobility.

Geography
The demon realm is constantly overflowing with the magic power of the Mamono. However, the concentration of this power seems to vary from place to place. When a human enters the demon realm, exposure to this power will cause them to undergo changes, with men eventually becoming incubi and women becoming Mamono (usually Succubi). The greater the concentration the are exposed to, the faster this transformation will take place. Areas with extremely high concentrations are also known for producing Dark Matters.

Plants
Just like humans, any plant that comes into contact with the Demon Realm will be corrupted in very lewd ways.

Tentacle Forest Undead Grey Lamentation Mushroom 

Depravity Fruits
Although their exact properties are unknown, they are believed to turn women into Mamono.

Products

There are also weird and lascivious products created from monsters.

Inhabitants
In addition to the Incubi who inhabit the Demon Realm, the mamono residing there include:
 * Arch Imp
 * Baphomet
 * Beelzebub
 * Bicorn
 * Dark Elf
 * Dark Matter
 * Dark Slime
 * Devil
 * Dhampir
 * Doppelganger
 * Dullahan
 * Gazer
 * Imp
 * Lesser Succubus
 * Lilim
 * Succubus
 * Vampire