Spirit

Spirits are spiritual bodies used by Gaia as a sense of touch, and anything that interferes with them is considered a contradiction. There are several types of spirits and despite the fact that they can be found everywhere only those humans who possess a spiritual affinity can perceive them. Spirits are generally harmless to people, but those of the elemental class are of such a dimension that they can be perceived and interact with people by taking a physical form. Presently, science cannot interfere with spiritual bodies and modern Magecraft cannot reproduce mysteries of such scale.

Nature

There are many spirits born from human folklore and human traditions due to humans being able to "engrave" a Thaumaturgical System (魔術系統, Majutsu Keitō^?) upon the World ─ a body of preestablished rules, fomented per the faith of the populace. If it is believed that the subject of a mystery "exists," the World permits its existence. Definite affirmation of said belief is not required, so even though the majority of modern humans reject the existence of ghosts, modern science cannot outright demonstrate that they do not exist, and, thus, within the unconscious, there lurks the vague suspicion that "they might indeed exist." This sort of "suspicion" falls under the category of "faith." "Ignorance" is the force that opposes "faith". If the existence of ghosts is itself utterly unknown, faith cannot foment.

Beings without physical form have a Spiritual Body (霊体, Reitai^?), that with spiritual properties where a shape is constructed without components with physical properties. Differing from a Material Body, that which is identical in structure to flesh bodies, that cannot walk through walls and becomes injured when beaten, spiritual bodies are capable of completely disregarding such physical interference. Without conceptual or magical properties, those with a Spiritual Body cannot be harmed with a baton or sword, and such attempts will only hit empty space. Those that can switch between both properties, such as Servants, have advantages and disadvantages in both states.

Categories

Elemental

Elemental (精霊, Seirei^?), the general term for the spiritual bodies (霊体, Reitai^?) of dead animals, nature spirits born from nature and the artificial created Guardian Spirits. Lower class spirits such as ghosts and apparitions are not included in this category. Most of these spirits do not necessarily have a human form and most of them cannot be perceived by humans.

Elementals don't need human "faith" in order for them to exist and they have the power to adopt a physical form by using the images of humans to shape their bodies. Still, even if the shape turns out to be close to that of humans, their values and logic is still unlike than those of humans. Fairies that grow to a scale that can be perceived by humans become elementals and elemental-class incarnation, by wearing humans' imagination as shells, becomes possible. True Ancestors who are, classified as a type of large fairy, fall into the category of an incarnated elemental.

Despite being a general category for all sorts of spirits, the term “Elemental” usually refers to spirits from nature when used by itself. The likes of the Lady of the Lake, the True Ancestors and others mediators of nature are first and foremost Elementals before being part of any other category. Incidentally, Elementals like the True Ancestors who are, classified as a type of large fairy, can become Demons when they drink human blood.

The mediators of nature are capable of using Marble Phantasm to materialize a phantasm, a vision and to manufacture their dwellings. Said dwellings are, despite their otherworldly aspects, still part of the natural world. As such, there are times when humans accidentally stumble into them.

Divine Spirit

Main article: Divine Spirit

Heroic Spirit

Main article: Heroic Spirit

Animal Spirits

Animal Spirits (動物霊, Doubutsurei^?) The spirits of dead animal's. Differently, as by the souls of dead humans, who are generally formless existences, animals retain their form from their former lives. But they are, just as Human Spirits, able to consume the souls and minds of people and convert them into energy. The basic abilities they had from the time when they where alive still remain but they don't change from such nourishment, as they only become tougher as their magical energy capacity increases.

Kitsune and Inukami

Kitsune and Inukami (狐、犬神, Kitsune, Inukami^?) The traditional nine-tailed fox and dog-familiar spirits of Japanese folklore, they are attributed of being the source of people’s insanity by possessing them. Also, in cases where a demon possession causes the emergence of multiple personalities due the host surrendering his rights of ego, the resulting alternate persona is said to be these spirits themselves accordingly with Japanese beliefs. However, unlike the nonsensical accidents that are the Western demon possessions, there is a definite reason and “will to curse” behind the cases of possession that are brought about by these spirits.

Neco Spirit

Neco Spirit (ネコ精霊, NEKO Seirei^?) refers to the type of spirits that reside in the Great Cat's Village. Members of the race include Neco-Arc, Neco-Arc Bubbles, Neco-Arc Chaos, Neco-Arc Evolution and Neco-Arc Destiny.

The Neco Twenty-seven Cats (猫27キャット^?) or Twenty-seven Cats (二十七キャッツ^?) include:

1. First Neco-Arc (はじまりのネコアルク^?)
2. cosmo murder
3. The Little Sister of the Fake Milk Scandal Cat (偽乳疑惑の猫又妹^?)
6. Makidera BEAUTIFUL (きれいな蒔寺^?)
7. Himuro STRANGE (.へんな氷室^?)
8. Yukika BAD (わるい由紀香^?)
10. SSF Sleeping in the Kotatsu (虎竜で眠るSSF^?)
12. The Strongest Kariya~n (最強のカリヤーン^?)
13. Experience Kohakki (エクスペリエンス・コハッキー^?)
14. Stheno CHASTE (貞淑なステンノー^?)
15. Euryale GLORIOUS (爛漫なエウリュアレ^?)
16. Eiichirou Version Sajou Ayaka (エイイチロー版サジョーアーヤカ^?)
18. True Identity Unknown Princess Fortune (正体不明系魔法少女プリンセスフォーチュン^?)
19. Iron Fist Violinist Ries (鉄拳ヴァイオリスト・リーズちゃん^?)
20. White Len (白レン^?)
21. Spotted Len (ぶちレン^?)
22. Calico Len (三毛レン^?)
23. Striped Len (縞レン^?)
24. Master Panda (パンダ師匠^?)
25. NG Akiha (NG秋葉^?)
26. Bread-making Amalgamation Giant God Kiitsuii-chan (製パン合体巨神キッツィーちゃん^?)
27. Cock Robin MAGNIFICENT (華麗なるコマドリー^?)
EX. Forced to Work, Neco-Arc Chaos (働かざる猫カオス^?)

Nature Spirits

Nature Spirits (自然霊, Shizenrei^?) As the name states, a spirit born from elements of nature such as plants, soil, gemstones, natural phenomenons and etc. Ores and jewels that have been beneath the surface for an extended period of time are said to be capable of easily giving birth to these kinds of spirits. Their spiritual body's are formed by the will of the planet earth and they gain power from nature itself. Only the spiritual bodys of the nature spirits, who are wanted by the planet as a defense against the resource-plundering actions of humans, can receive a body made out of flesh from Gaia. These supernatural entities are known as the Transcendent Kind. One class of such entities are referred to as True Demons (真性悪魔, Shinsei Akuma^?), who possess the capacity to warp (interfere with) the external world by virtue of their being born from the laws of nature -- and therefore being connected to it.

Jinn

Djinn (ジン, Jin^?) The wind demons of Islamic tradition, well known for being very mischievous. With bodies made of gas and smoke, they can float in the wind and are mostly invisible, but are capable of producing solid forms when necessary. In those cases, they preferably take the shape of an ogre with the face of a dog and the back of a cat, but cases where they take the appearance of a beautiful human or some beast such as snakes are not unheard of. Their exists a curse which is passed down in the Middle East that is used to ward off storms and Jinns. It is used by True Assassin in the Heaven's Feel route of Fate/stay night's Fifth Holy Grail War.

Guardian Spirit

Guardian Spirit (守護精霊, Shugoseirei^?) is a classification of spirit that comes from the result of merging an Animal or Nature Spirit with a human soul. It is not something that happens naturally, but rather is something that is made by the hands of men in order to give human values to something that is not human. The spirits of humans are of a much lower rank than the nature or animal spirits and are thus absorbed in, but as a result, it acquired knowledge as a human, and gradually acquired a human's value. Theses Spirits must be bound, to objects or to places, inorder for them to stay in this world. It takes quite some time for the human spirits to gain control of themselvs and to gain their own body. They are considered to be below other types of Elemental, but have the potential to become Holy Spirits (聖霊, Seirei^?). These Holy Spirits can possess Mystic Eyes, which are designated as Jewel under the Noble Colors system. They surpass the Gold-ranked Eyes of the Dead Apostles and are exclusively possessed by Holy Spirits and Magical Beasts from the Age of Gods. In order to materialize themselves, they require a supply of prana beyond that of most people. Guardian Spirits cannot be observed by anyone, except for the Master they are connected with, in their spirit form. They can talk with each other and the Guardian Spirit can go scouting, by flying in their spirtual form. The best examples for these kind of spirits are Nanako who inhabits the Seventh Holy Scripture from the Church and the Argon Coin possessed by Medea.

Lower-class Spirits

下級霊 - Kakyuurei

Vague, generally formless existences that can only acquire a definite identity by “possessing” an image.

Wraith

Wraith (亡霊, Bourei^?)

Wraiths

, also referred to as Human spirits, are souls of dead people that remain attached to this world due to past grudges, regrets and other sorts of unfinished business that they had during life. As such, they tend to haunt places, items or people that are related to their unfinished business. Normally, direct physical intereference on the part of these ghosts are low. As spiritual body's they usually have to act through some sort of medium, by putting it under its domination, in order to conduct interference. However, as they are no longer something that belongs to this world, their existence is something that degrades with time and they are bound to disappear eventually.

But as they are Human Spirits they are able to consume the souls and minds of people and convert them into energy. The basic abilities they had from the time when they where alive still remain but they don't change from such nourishment, as they only become tougher as their magical energy capacity increases.

There is also an interesting relationship between Wraiths and Heroic Spirits. If a hero of fictitious origins is summoned by any reasons, a Wraith of an individual that possessed traits similar to that fictitious hero will be created to temporarily play his role. Such was the case of Sasaki Kojirou. However, it should be noted that all of the Hassan i Sabbah that qualified as Servants of the Assassin class per the uncorrupted rules of the Fuyuki Grail War are technically wraiths rather than Heroic Spirits.

The Dead Apostle Ancestor Stanrobe Calhin is referred to as the First Wraith, a disembodied soul would not dissipate for at least another 200 years. 

Apparition

File:Apparitions.jpg

Apparitions of the Fujou Building

Apparition (浮遊霊, Fuuyuurei^?), also referred to as leftover thoughts (残留思念, zanryuu shinen^?), are fragments of an already departed soul that gathered together to form an amorphous entity that is filled with nothing but the most primitive drive to live. A projection of someone’s past records which were stored in the surroundings. The traditional ghosts in the popular sense of the world, generally harmless as almost nobody can perceive them. Technically, they can still interact and even attempt to possess those with spiritual abilities, but as long as the target possess a strong ego they won’t be able to take over.

Examples include the spirits of the Fujou Building. The “fairies” controlled by Misaya Ouji and Len were made out of these kind of spirits.