Spirit

Spirits (精霊, Seirei) are one of the four main races, alongside Demons, Humans, and Gods.

Overview
Spirits are the living embodiments of traditions, legends, rumors, desires, fears, and hopes. When these beliefs become more widespread, a spirit based on them is born. Sometimes people's fear of fire leads to the creation of a fire spirit, and other times their faith in water leads to the creation of a water spirit. People's beliefs is what forms the source of a spirit; and as a result, spirits will cease to exist when their birthing stories are forgotten. Neither resurrection or time magic will be able to bring them back. They can also die when contradictions in their legends and rumors arise. Unlike demons and humans, spirits have no concept of reincarnation, though it is possible for a spirit to change its nature if the lore that forms its existence is changed. However, spirits are most influenced by the rumors and traditions that first created them, and contradictions to that can lead to their disappearance. Though if a particular rumor doesn't contradict a spirits original lore, it will not cause harm and will be added to the original lore, thus potentially granting new abilities.

An example would be the rumor that the tears of the Great Spirit Reno give birth to other spirits, which originally wasn't part of her lore but was later added due to complimenting her original lore and granting her that ability.

Powers and Abilities
Spirits are stated to be the embodiments of their respective rumors and traditions, as they are pure manifestations of legends, thus making them being made up of magic power. A spirits individual abilities are determined by their lore, as they gain whatever abilities other believe they have or they gain abilities based in the rumors that forms their essence. Unlike demons and humans, when a spirit casts their magic, they expend a portion of their source to utilize their magic. However, the lost essence is replenished easily so long as rumors and traditions remain, thus allowing them to cast magic with no adverse effects. Spirits whose rumors and tradition have been forgotten will disappear, and those whose legends are on the verge of being forgotten will develop the Spirit Disease, thus leading to their eventual disappearance. It is stated that spirits can survive and revive even from having their source destroyed so long as there is belief in their lore to maintain their existence.

Every spirit can have a temporary and a true body. Because their appearance is determined by their legends and rumors, they are more much powerful while in their true body because they are closer to what they embody. In addition, it's not uncommon for a spirit's personality to completely change between their temporary and true form.

Great Spirit
They are spirits that are born from influential tradition that is powerful, as their own power reflects that. An example would be the Great Water Spirit Liniyon, who demonstrated the power to wipe out half of Anos' subordinates in a single blow with the power of her true form. Another would be the Great Mother Spirit Reno, who was considered one of the most powerful beings during the Mythical Age.

Half-Spirit/Half-Demon
The offspring between a spirit and demon. Unlike full spirits who are born fully matured when their stories become well-known, half-spirits are born as babies without a legend or rumor to claim as their own. To fill their spirit side, they have to subconsciously take in newborn rumors or faint hopes, essentially things that haven't spawned a spirit yet. If those rumors and hopes spread to more and more people, then a half-spirit can live a normal and comfortable life. However, in most cases, half-spirits only live short lives because newborn rumors easily fade away and hopes are often crushed. When this happens, they get Spirit Disease (精霊病, Seirei-byō), which causes their magic power to weaken and their source to slowly vanish over time. It's possible to save them by spreading their rumors and hopes, but this doesn't happen often because half-spirits have no knowledge of what legends or traditions form their spirit side.