It is the source of all supernatural phenomena such as Magecraft or ESP, and beings such as True Ancestors, Dead Apostles, Servants, Spiritual Bodies, as well as Phantasmal Species show signs of Mystery. Mystery accumulates over time and grows stronger with age.
The word 'mystery' derives its etymology from the Greek mystêrion, the root of which, myo, means "to close or shut", and can be understood variously as shutting, concealing, and self-completion. A Mystery thus holds meaning specifically because it is a Mystery. If they were understood, they lost that force.
Magecraft is, in essence, Mystery. However, since the beginning of the Common Era, human history has been in the process of systematically expelling Mysteries. To the same degree the light of science expands, the darkness of Mystery recedes. No matter how magi resist this fact, this law remains unbent. The Mysteries of the Age of Gods have become so distant that even realizing them temporarily in the modern world is next to impossible. Humanity has reached the point where everything is explainable with human knowledge, from the workings of nature to the operation of the cosmos that was once the purview of the heavens, anything that was once beyond the ken of man. The decline of Mystery had been accelerating since the death of Solomon, the King of Magic, before the Age of Gods came to an end at the start of the Common Era.
This greatly affects Magecraft. A Magecraft that has had its nature revealed can't become a mystery, no matter what kind of supernatural methods it uses. It's now nothing more than another mundane method. For example, automatons have become a lost art in magecraft and the concept of Homunculus creation is steeply in decline because, as knowledge of the human body deepened and spread throughout humanity, to the point humanity accepted that there were no Mysteries to be found within their own bodies, they had lost the grounds to be fields of Magecraft. Even if one accepted the theory that the human body still is a black box, and the Mystery within it was not yet entirely erased, the fact that modern magi in the field can't compare to even antiques from hundreds of years ago is an undeniable fact. Magecraft thus gets weaker when it's exposed, though what is meant by that is not the magecraft of a particular individual, but all of magecraft and in the future, not the present.
Paradoxically, despite losing its power when propagated, a Mystery becomes more stable as knowledge about them spreads thanks to the system of Magical Foundations. Engraved into the World, its strength can be greatly influenced by the faith and the collective unconscious of the people.
In order to stem the degradation of Mystery, the Mage's Association was founded, and it began enforcing the Concealment of Mystery (神秘の隠匿, Shinpi no intoku?) to preserve the strength of Magecraft. It was previously something of an unwritten law, but became enforced over time, with the popularization and vulgarization of Mysteries being tantamount to a crime in the World of Magecraft. In fact, in the past, magi could even make a career of magecraft and be recognized by society, so long as they kept their magecraft a secret they would take to the grave, but now it has to all be kept under wraps. The Association feared that if they did not go that far, magecraft in the distant future would be reduced to nothing more than another product to be consumed and thrown away. In the world of Fate/strange Fake, Lord El-Melloi II estimates that the Concealment of Mystery won't last more than another five years, as they approach a time when anyone can upload high definition images to social networks in real time, notably thanks to smartphones. Once that happens, the ability of information to spread will outstrip the pressure to conceal it. As the danger of Mystery being recorded increases, either new methods of secrecy will have to be devised, like seeding dummy stories and label everything fake newsWP, or they will have to reveal something.
Mystery hasn't degraded everywhere however. Compared to the surface, the texture of the Human Order influences the underground much less, so traces of mystery still remain in the depths of the earth. For that reason, there will be fragments of things that have disappeared aboveground there, like pieces of Phantasmal Species. Islands as well, due to being isolated from the mainland, have had Mysteries from the Age of Gods remain longer, such as Britain, the "navel" of the planet, and Japan, whose Age of Gods outlasted Britain's. Continents are firmly part of the human world, thus, as countries are connected by land, so the rewriting of the physical laws proceeded quickly.
If two different types of Mysteries collide with one another, the stronger Mystery will overwhelm the weaker one. It is through this law that Lugh Beowulf is able to remain invincible against modern magecraft; because he has 3,000 years' worth of Mystery, which is far more than any modern magecraft has, he is able to simply ignore any effects that magecraft would have on him. Another similar case is Wuzhiqi, who is a Xian and thusly there are not a lot of spells that can affect her in the modern world.
Time being of exceedingly high value in thaumaturgical applications, a Mystery strengthens the longer it has existed. For example, a family's Magic Crest becomes strong by having new accomplishments added to it by every generation to have received it. With a eight-hundred-year-old parchment, one may forge a Golem that can easily destroy one or two experienced magi. Likewise, certain items that have a long history and age can also show signs of Mystery, as in the case of the centuries-old katana that the Ryougi possess, Kanesada Kuji. If they are severely damaged, however, they will lose all the Mystery they have accumulated. Just as a jewel carried by many different people over a long time begins to be stained with their thoughts, making it easier to use in Jewel Magecraft, a tool bearing the feelings of many people would also begin to develop its own kind of Mystery. While for most objects that Mystery stays concealed forever, in some rare cases it can bloom forth, like the TsukumogamiWP of Japan.
It is also possible for a human's body to reach the level of a Mystery, such as with Shiki Ryougi. There are also the cases of Doctor Heartless, a magus who got his heart stolen by Fairies, and the Mixed-Blood Kouma Kishima, a true Crimson Red Vermillion, who have both become a mystery.
 Fate/complete material III: World material - FAQ with Nasu: Miscellaneous, p.136
Q: Who would be stronger if Servants fought the 27 Ancestors?
Q: Who would be stronger if Servants fought the 27 Ancestors? Servant's also have superhuman battle ability, but the 27 Ancestors are also superhuman monsters.... I got the impression that ORT, Primate Murder, Altrouge Brunestud, and so on were obviously stronger than Servants.
A: All I can is they're both powerful.... They're both beings that live in mystery, so the only thing that can be said is that it all depends on the situation the moment it comes done to ""having the means of killing the other guy somehow". Among those, Earth rules won't even apply to ORT in the first place and Primate Murder has the super advantage against primates so they're in a league of their own, I suppose. Speaking of which, for one Primate Murder, seven Guardians would be the appropriate amount.
 Kara no Kyoukai Special Pamphlet - Encyclopedia: Magecraft [Others], p.038-039 [T]
A general term representing activities that artificially re-enact Mysteries/Miracles.
Although there were some differences depending on traditions and schools, the basic principle was still "the transformation of the magical energy that exists within the practitioner or the environment".
The practitioner would issue Commands according to the Foundation (System) of his school, and this would cause the execution of a predetermined Program.
Magical energy was the electrical current required to deliver the command.
Although magecraft gave the impression of omnipotence, it fundamentally produced Mystery through the principle of equivalent exchange.
It was possible to transform one thing into another, but it was impossible to produce something from nothing.
However, the essence of magecraft as a discipline was to challenge that "Nothingness", and endeavor towards the impossible. Large-scale spells such as the so-called Grand Sorceries, Grand Rituals were really purposeless if not for attempting to reach " " (Kara) or True Magic.
Kara no Kyoukai was a story of one magus' attempt at challenging "Nothingness".
- Kara no Kyoukai Volume 5: Paradox Spiral (Enjoh Tomoe) - /6
- Mahoutsukai no Yoru - Chapter 6: "Like a Dog"
- Lord El-Melloi II Case Files Volume 1: case. Adra Castle Separation - Chapter 2 Part 3
- Lord El-Melloi II Case Files Volume 1: case. Adra Castle Separation - Chapter 4 Part 1
- Lord El-Melloi II Case Files Volume 1: case. Adra Castle Separation - Chapter 1 Part 2
- Garden of Avalon - Chapter 02: The Light of the Stars
- Lord El-Melloi II Case Files Volume 2: case. Twin Towers of Iselma (Upper) - Chapter 3 Part 4
 Lord El-Melloi II Case Files material - Encyclopedia: Magical Foundation [Magecraft/Other], p.109
Magical Foundation [Magecraft/Other]
A magical theory engraved into the world. Its strength is greatly influenced by the faith and the collective unconscious of the people.
As a Mystery propagates, it loses power. However, the reason they become more stable as knowledge about them spreads, though it may seem contradictory at first glance, is because of this system of Magical Foundations.
In the present day, the most widespread and most powerful Magical Foundation is the “Teachings of God,” used by the Holy Church.
Of course, there also exist families who develop magical formulas entirely independent of such Foundations, and weirdos like Flat who “build an entirely new formula from scratch every time.”
- Fate/strange Fake Volume 2 - Chapter 6: Day 1, Noon "Two Archers and..."
- Fate/strange Fake Volume 5 - Bridge Chapter: "Rondo of the Outsiders"
- Lord El-Melloi II's Case Files Volume 8: case. Grand Roll (Upper) - Chapter 2 Part 4
- The Adventures of Lord El-Melloi II Volume 3: The Devil of the Wandering Sea (Lower) - Chapter 3
Fate/stay night - Fate route - Day 10: skyscraper - Sword of Promised Victory
It is the law that a divine mystery will be eliminated by a greater divine mystery.
- Mahoutsukai no Yoru - Chapter 12: "Witch on the holy night"
 Mahou Tsukai no Yoru Privilege - The Magician's Basic Rhythm: Lugh Beowulf, p.028-029
- Birthday: January 1
- Height: 134 cm
- Weight: 35 kg
- Likes: The person who gave him his first defeat
- Dislikes: Annoying things
- Day of Decisive Battle: None in particular
- Magecraft System: None in particular
- Regression to the Age of Gods/Quality: A
- Regression to the Age of Gods/Quantity: C
- Regression to the Age of Gods/Composition: Phylogenetic Tree up to the 18th century
Nasu's comment: A still living, genuine phantasmal species. His origin itself was long long ago, but it wasn't until the 18th century that he fell as a droplet on the werewolf village. A two thousand year class vintage monster. He is the natural enemy of the magi of the Common Era. In a contest of pure magical energy, attacks may still work on him, but when it comes to magecraft, it'll be absolutely invalidated. He's a life-form that's sort of like a relative to Arcueid, so he has an aura similar to Arc. It is a bit boorish to mention it but he doesn't have the concept of gender. Although it is very unlikely, in the case that he found a partner, he would be able to freely choose his own gender to compliment theirs. It's just like the manga "They Were Eleven!"
Koyama's comment: As a werewolf, I drew various forms of him. Between the complete wolf form and bipedal form, Beo can transform on the spot into the most fitting form for the action that he wants to do. Just as humans don't put any conscious thought into moving each induvial finger when they eat food with chopsticks, if he wants to run he does it on 4 feet and if he wants to grab something he does it with his "hands". Conversely he's also able to consciously control them. Normal werewolves can't take the form of a full wolf and their transformation is slow. In Beo's opinion that's so half baked it's meaningless, and it's so funny to look at that it spoils his mood. That's all I know. His clothes are supposedly to Touko's taste.
- 生日: １月１日
- 身長: １３４ｃｍ
- 体重: ３５ｋｇ
- 好きなもの: 最初に自分を負かしたひと
- 嫌いなもの: うるさいもの
- 決戦の日: 特になし
- 魔術系統: 特になし
- 神代回帰 / 質: Ａ
- 神代回帰 / 量: Ｃ
- 神代回帰 / 編成: 十八世紀までの系統樹
まだ生きている生粋の幻想種。発生そのものは大昔で、雫として人狼の里にこぼれ落ちたのが十八世紀。二千年クラスのビンテージモンスター。 西暦以降の魔術師にとっては天敵で、純粋な魔力勝負ならまだ攻撃は通るが、魔術となると片っ端から無効化されてしまう。アルクェイドの親戚 みたいな生き物なので、なんとなくアルクに近い雰囲気に。語るのも野暮ではあるが、性別の概念はあまりなかった。まずあり得ない事だが、つ がいの相手を見つけた時、その生き物に合わせて性別を決めることも。「１１人いる!」ですなー。
人狼ってことで、様々な形態を描きました。完全な狼形態から二足歩行形態の間でベオがとりたい行動に対して最適な形態に即座に変形します。 人が箸で食事する際、指一本一本をどう動かすかいちいち意識しないのと同様、走ろうと思えば四つ足に、何か捕まえようと思えば「手」に。逆 に意識してコントロールすることも可能。普通の人狼は完全な狼形態にはなれないし、変形も遅い。ベオに言わせると中途半端だしイミわかんな いwww見てると気分悪くなるよね wwwみたいな。以上うんちく。服は橙子さんの趣味という想定です。
- Birthday: January 1
- The Adventures of Lord El-Melloi II Volume 1: The Man Who Devoured God - Chapter 4
- Fate/Apocrypha Volume 1: Apocrypha: Great Holy Grail War - Chapter 2
 Kara no Kyoukai - Chapter 5: “Paradox Spiral” Movies Q & A Pamphlets
Q: Will it be possible to repair the antique katana now that it’s broken?
Q: Will it be possible to repair the antique katana now that it’s broken? <Yasunosuke>
Nasu: Even if it was reforged, the years it had accumulated before would be lost.
Takeuchi: A lot of people asked this question. Since I thought it was going to be Shiki’s final weapon, too, I was pretty shocked when it broke almost as soon as it finally appeared!
Nasu: That’s how ultimate weapons should be.
- Lord El-Melloi II Case Files Volume 2: case. Twin Towers of Iselma (Upper) - Chapter 4 Part 3
Melty Blood Actress Again Current Code - Powered Ciel's Win Quote versus Shiki Ryougi
"A composition that is neither natural nor artificial. Eastern ideology can be profound at times. It can create people like you who has attained the level of being a Mystery while still being human."
- The Adventures of Lord El-Melloi II Volume 3: The Devil of the Wandering Sea (Lower) - Chapter 6