Theoretically, as many types of oni exist as there are types of humanoids, although in reality, certain types of oni are much more populous than others. The ogre mage, an oni associated with ogres, is the best-known and most commonly encountered type of oni, for reasons that still send scholars of oni lore into spiraling arguments with seemingly no end. Beyond those, the atamahuta (ettins), ja noi (hobgoblins), nogitsune (kitsune), and wind yai (cloud giants) are relatively well known. Oni with associations to bugbears, great cyclopes, stone giants, trolls, troglodytes, and other races exist as well. And above even the mighty void yai there exist the oni demigods—entities of nearly incomprehensible power known as the oni daimyo.
Known Oni Daimyo
Countless oni stalk the world, slaking their greed and bloodlust to the misery of humanoids. The great leaders among the oni, beings known as daimyo, are as numerous as the nations of the world, and all oni seek to climb the rungs of power to become such powerful entities. The following list includes oni daimyo that have power in ways that make them known and feared outside their own domains. Most of these nefarious oni command armies or control points through which other oni can enter the world.
Akuma, the Horned King (ogre mage)
Chimon, Hunter of Blood (ogre mage)
Guyuku, the Sea Devil (water oni)
Inma, Empress of the World (void oni)
Muronna, the Dark Mother (ogre mage)
Nataka, the Red King (fire oni)
Onmyuza, Dancer in Flesh (ogre mage)
Ushitora, Keeper of the Oni Gate (void oni)
Uzumae, Daimyo of the North (kuwa oni)
Yabu, Lord of the Kazan Caldera (fire oni)