Yokai

Yokai within Hisari are split into two categories: corporeal and incorporeal. Sometimes they are related to undead or ghosts. While other times, they are oddities formed with both magical and spiritual energies. Yokai are as diverse as any other monster, differing in origin, shape, and size. Some are household objects brought to life by emotions, while others are animals which were never normal and knew magic all along. Others are bloodthirsty, vengeful spirits of nature or those wronged in life, returning to haunt their oppressors. While both of them are incredibly different, yokai is a category which encompasses all of them.

Incorporeal Yokai

Incorporeal yokai are almost exclusively fiends, existing in the same ranks as demons, devils, yugoloths, and other fiendish beasts. They are their own kind of fiend, however, and their native plane is the Dark Forest. They are usually born from grudges, curses, and the distorting negativity of the mortal heart. When a person feels great hatred, sorrow, lust, or suffers greatly, a yokai may form in the Dark Forest to mirror them as a dark shadow of their corruption and pain. The yokai instinctually seeks its own source, feeding off of it until the well runs dry, and then it seeks that which is alike its first prey. The form of a yokai varies based on the origin of its birth.
Should they become strong enough, a yokai may discover their own name and develop individuality. Once they know their own name, a yokai forms the same connection to the Dark Forest that a demon has to the Abyss, or a devil has to the Hell: should they die outside their plane, their body will reform some time later.
They are often drawn to the longer living races such as Elves and Dwarves by instinct, as the age and vanity of those species offers many chances for their kind to form, and their long lives allow for much suffering and pain to feed off of. 

Corporeal Yokai

Corporeal yokai are the most varied of their kinds, coming in all shapes and sizes. Mostly hostile creatures, they are entirely native to the Material Plane. They quickly fall into a predator-prey lifecycle, creating natural hierarchies amongst each other as animals would. 
Their main difference between them and normal animals and monsters is their intelligence. Whereas most creatures follow natural instinct or their own biological needs, corporeal yokai have a tendency to scheme, connive, and make long-reaching plans. They have a penchant for sneaking their ways into the hearts of men, corrupting them for their own desires, or ultimately utilizing the suffering and corruption as the proverbial spice to their meals. 
These creatures tend to live incredibly long lives, gaining notoriety in the areas in which they exist in, and being a constant source of ire to the local populace. Corporeal yokai, however, are powerful, and therefore are often left to live their lives outside of intervention by powerful forces. Samurai under the orders of their daimyos tell tales of any of these yokai they have slain, being seen as a large badge of honor, and many a young samurai have lost their lives to these beasts in an attempt to gain such notoriety. 

Daiyokai

Known as yokai lords, the name literally means "great yokai", designating them a special bunch even among the various yokai in existence. They are the equivalent to archfiends and archdevils, except usually more tribal and nomadic. They are yokai who have existed for such lengths of time that they reach far beyond their own kind or are created from such massive tragedy or suffering that they are born differently. 
Yokai lords are powerful, beyond the need to feed on negative emotions (though they do partake), and often have greater designs. They are incredibly pure-blooded, which makes their in-humanness all the more obvious and frightening. They can restrain themselves in a humanoid form, which often looks very handsome or beautiful, with small giveaways to their true nature. More and more often they adopt these forms as their default, using it to get close to humans for often nefarious purposes.
Among their kind, Daiyokai are treated like gods; lesser yokai of their breed serve them instinctually and without question. They tend to fall into the categories of vicious hunters, or shrewd manipulators. Many times in history these yokai have installed themselves as lords or advisors, and have often terrorized a large province as a beast of the night. Daiyokai are often known to have a bleak fascination with mortal beings to such a point that it is common for them to keep concubines and consorts to please or serve them - a common source of Hanyou. 
Often, Daiyokai find demons or misguided brutes and devils to be overly pompous charlatans. They see themselves as above the base conflicts of the blood war and feel their fiendish counterparts are short-sighted fools who lack any sense of pleasure or tact.
However, their arrogance has its own strange quirks. Among their lesser kin, human interactions are almost seen as taboo, as yokai culture is held in superior regard. Additionally, they can often enforce an almost hermetic or secretive lifestyle amidst their lesser forms, seeing themselves as being the only ones deserving of a lord's lifestyle. They maintain an almost feudal-like society, mirroring the laws of men that they claim to deride. 
They value strength above all else, with open contests for who is the lord of the tribe being far and few between. There are a few exceptions to this, namely amidst the warring Oni who take this ideal to the extreme. If a yokai is weaker than another, it is often forced to obey the stronger and pay tribute in exchange for protection. Daiyokai rarely come into conflict with one another, as they stick to their own territories and their own lifestyles. However, when they do, all out war between them is inevitable.

Yokai have the creature type of fiend (yokai), making them a distinct creature type. Spells that detect fiends should be able to detect them as well, and if a feature or trait checks for creature types and can include demons, yokai should be considered a target of that trait.