Whilst Pale Rider is named after one of the Four Horsemen of the Apocalypse, Pale Rider summoned in the False Holy Grail War is a completely different being from the Pale Rider described in the Book of Revelation.
In conclusion, "he" was a being as foreign as could be. Pale Rider is the embodiment of pestilence given form by the False Holy Grail. Differing from those called Heroic Spirits, he is only one in name. Far from a "hero", it cannot even be called a Villainous Spirit or Demonic Spirit. Some regions have called it a "curse", and some religions have denoted it to be "divine punishment." It is "disease", that which has existed since time immemorial and that which will continue to exist far into the future. It has lived a shorter life than anyone, and yet has lived a longer life than anyone. Called a horseman who has brought calamity to all, it is that which "let loose" the Black Death that killed thirty million people and came "under the name" of Spanish Influenza that killed fifty million people. Given a physical presence despite not being a Heroic Spirit, it continues to exist in that moment to take the lives of those on the planet to provide itself nourishment for life to begin anew.
Pale Rider appears as a black cloud, a vague form with no particular shape.
Pale Rider is not based on a hero, or even a human, so it lacks a persona and was only given knowledge by the system of the Holy Grail War. It does not understand human emotion, and it only acts for Tsubaki Kuruoka and it's own instincts. It is akin to a robot created without emotions or internal monologue, a mere formless mass of awareness and knowledge about the Holy Grail War. It speaks with a grating sound like the "scraping noise of swarms of insects battling one another" and it's words are dread incarnate.
Rider is summoned by Tsubaki inadvertently after she gains Command Spells in the real world and invokes the summoning ritual in her dream world with her desperate pleas for her parents not to leave her alone. Despite "his" nature, she is not scared of "him" because she will no longer be alone. After she introduces herself, "he" takes her parents into the dream world, "dancing" together to forget her abuse and grant her desires. Though she smiles at "him" and thanks "him", "he" merely continues to exist without even giving a nod in reply. She gives "him" the nickname "Mr. Black".
During the battle between False Archer and False Lancer, Rider goes to stop the battle, as it was scaring Tsubaki. False Lancer senses Rider approaching and also notices his nature as a curse of death, which would be especially harmful to them. Because of this, Lancer and Archer stop their battle, though they wish to continue on later, without interruption. Archer also decides to look for the opportunity to take out Rider later, so he won't interfere anymore.
As the war gradually progresses, Rider finds and infects more and more victims for Tsubaki. At one point, Rider seized a number of veterinary hospitals in Snowfield in order to provide Tsubaki with animals to play with. Jester Karture, a Dead Apostle who is the Master of False Assassin, later arrives in Tsubaki's dream, being accepted by her and, by extension, Rider.
Jester informs Tsubaki of the battle between True Berserker and True Archer, and their Masters, that is putting the people in the area in danger. This causes Tsubaki to send Rider to "save" the endangered people, with Rider infecting them and taking them to the dream world.
Flat Escardos and Jack the Ripper arrive at the hospital searching for False Rider. However, after detecting his immense aura of death, they decide to retreat.
A number of other parties in the war also find out about Tsubaki being Rider's Master, with many of them arriving to fight outside her hospital. Eventually, on Jester's signal, False Rider draws everyone at the battle into the dream world. Pale Rider kills three of Alcides' Diomedes.
Tsubaki greets Sigma and False Assassin and introduces them to her friend Mr. Black. They see False Rider under a tree and are frightened despite Tsubaki assuring them that Mr. Black is friendly. Later, when Sigma tries to warn Tsubaki's father about Tsubaki being threatened in the real world, False Rider summons the Cerberus from True Archer's King's Order to guard Tsubaki's house in the dream world, enlarging the creature from the size of an elephant to much larger than the house.
El-Melloi II conjectures that False Rider is a Heroic Spirit related to pathogens, or possibly a being that had been treated as symbolic of sickness itself in an era that lacked the concepts of bacteria or viruses. Yuukaku Kuruoka speculates that he must be the embodiment of a concept, although it's hard to determine whether this is death, nothingness, or disease. In Japan, a yōkai called a ‘yanari’ was created to explain houses creaking. That was a type of folk Magecraft, deciding that it was a conscious being, giving it form, and taking mental measures against it. However, considering False Rider's power, Yuukaku believes it must be an entity recognized on a global scale. Death is everywhere, not just in the land of the dead. Mystically speaking, the concept of death exists even in air, water, stone, and earth.
The reason Pale Rider is capable of wielding immense power is that he is an embodiment of a portion of the World’s logic. Pale Rider's true nature is that of a system-type Servant designed for carrying death to humans. Because of this, Jester Karture refers to him as "Cursed Servant of the Planet." Although he is a Heroic Spirit in name, the terms "hero", "Villainous Spirit", "Demonic Spirit" or Wraith don't suffice to describe "him." In some places, “he” was described as a “curse”, while in some religions, “he” was said to be “divine punishment”. In the Holy Grail War, Servants are selected from the past and the future—from every age of Human History. The classes into which the Servants are summoned transcend time. A Hero of the past, known only via lore, may be summoned, as may a Hero of the future, not yet born into this world. From that perspective—“he” has existed since time immemorial, and “he” will likely continue to exist far into the future. “He” has lived a shorter and a longer life than anyone. And so, “he”—a being with physical presence, though not a Heroic Spirit— Even at this very moment—there is no doubt that “he” continues to take the lives of those that live on this planet. Indeed, perhaps “he” does so that “he” may “himself” provide nourishment for life to begin anew. The reason he is summoned as a member of the Rider class is that “he” has ridden “his” way to dominance over the world, whether he was riding on the wind and the waters, or the birds and the people. “He” was an embodiment of calamity, and the people gave “him” an alias that reflected that. Perhaps that spurious assignment of a personality to “him” was the most important reason that “he” was summoned as Rider. At one time, “he” let loose the Black Death, which killed thirty million, And at another time, under the name of the Spanish Flu, “he” killed fifty million. “He” was the horseman who brought calamity to all. His alias: Pestilence. Pale Rider also calls himself "Death," one of the four horsemen of the Apocalypse.
« “I am swords.” “I am beasts.” “I am thirst.” “I am hunger.” “I am the bearer of death.” “I am the player of death.” “I am death.” “I am death.” “Death.” »
Pale Rider lacked a mind to begin with, however, when he was granted knowledge of the Holy Grail War, he was able to manifest as a Servant. His personality continues to learn from the moment it is summoned by adapting to its Master's reactions. It is possible that it could become a completely different entity each time it’s summoned. Because he is a system without will, he behaves as a tool should, searching to complete the wish of his Master. During the True and False Holy Grail Wars, however, Pale Rider struggles to make true Tsubaki Kuruoka's wish to "Become a Magician," since it far exceeds the capabilities of its systems. An ordinary Familiar, no matter how intelligent, would have answered, “That’s impossible.” However, Pale Rider was different. Because it had been given knowledge as a Heroic Spirit, it possessed a possibility, the Holy Grail. It was hardly a certain method. No matter how low the probability, however, Pale Rider, the Servant of the concept of death, would present that method. The Third Magic, which had been lost to the world with the creation of the Greater Grail. Magic was outside natural law and was therefore impossible to reproduce using a wish-granter within the bounds of natural law. But in the case of the Third Magic, which was linked to the Grail, and only in that case... there was a possibility. Enkidu believes that if Pale Rider were to fuse with the Grail, and therefore the Black Mud inside it, the whole World would be in trouble.
Pale Rider is able to conceal his presence almost completely. Even Gilgamesh never imagined that it would be able to conceal its tracks in such a form. In fact, Gilgamesh wasn't able to find him even after looking for him in the entire city of Snowfield. Only Flat Escardos was able to notice its vague presence covering the city, and was able to track the source to the hospital where Tsubaki Kuruoka was located. Once Flat and Jack the Ripper got close enough to the room of Pale Rider's Master, Flat noted that if the stuff that spread into the hallways through the decontamination room is a black fog of Magical Energy... then what surrounded the entrance to her room is part of a giant waterfall. Although Jack couldn't see it clearly, his killer instincts were raising an alarm. They were warning him that the sickroom was filled with the same air that must have surrounded him in the fogs of London. They were warning him that ahead was Death itself.
Jack the Ripper says that he could probably manage to kill Tsubaki if he used his Noble Phantasm, but he can’t say for certain. He claims that using bombs to destroy the entire hospital might be a better idea. It is also stated that even a Heroic Spirit as great as Alcides has no choice but to flee when meeting Pale Rider. Alcides had no way of knowing exactly what False Rider was. Still, all his accumulated experience and the senses honed by the deadly combat he had just been engaged in told him that it was no ordinary being. In the face of Pale Rider's attack, Alcides chose to sacrifice three of the four Mares of Diomedes while he retreated riding the fourth one. Gilgamesh knows the fact that Enkidu has no weaknesses well. If there is one exception, it would be the death that hounded him — Ruin itself, none other than the curse of death that the gods placed on it back when it was alive for helping Gilgamesh slay the Bull of Heaven. This is the reason why Enkidu describes Pale Rider as their natural enemy. Despite Pale Rider wielding immense power, Gilgamesh has claimed on two occasions to be capable of terminating him with one swing of his property.
Pale Rider appears within Kuruoka's dream world, letting loose a black fog over the streets. The contract is formed only within the dream, so none outside are aware of it. "He" is able to facilitate her unconscious dream magecraft by bringing people into the dream world by infecting them from outside, many black spots like bruises appearing of their bodies, and causing them to fall unconscious. While also absorbing their magical energy instinctively, "he" does not take directly from their life force, so their bodies are only disabled. They appear within the dream world with the same black spots covering them, and "he" manipulates them to remove their original personalities and instead become living dolls following Kuruoka's idea of how they should act.
Within the Real World, Pale Rider travels on the wind, and is capable of physically expanding to a large expanse. By expanding much like a Bounded Field, he is able to surround and seal off the City from the outside world, preventing any entity from entering or leaving, returning any and all humans attempting to leave back into the City. During the enemy convergence to Tsubaki's house upon realizing her status as a comatose child, False Rider revealed the ability to even forcibly bring powerful Heroic Spirits such as Alcides and Huwawa into his Dreamworld. Pale Rider was also capable of stealing Cerberus, one of the Noble Phantasms owned by Alcides thanks to King's Order. When summoned by Alcides, Cerberus doesn't possess its former divine beasthood due to no longer possessing Hades’ blessing. However, under Pale Rider, who closely resembles Hades and the Underworld, Cerberus gets closer to its original strength, especially the more dead people it takes, allowing its combat abilities to eventually match those of a high-ranking Servant. Whereas it was at most the size of an adult elephant previously, the first time it appears under Rider's control it is easily over fifteen meters tall. It keeps growing, until its appearance recalls a three-headed kaiju out of a giant monster movie.
- Contagion (A Rank): The Skill of expanding one's territory by splitting itself into viruses and bacterias, then infecting other lifeforms. The infected have their body and mind under its control, and the mind is dragged into the world created by its Noble Phantasm. Sometimes it also absorbs Magical Energy and other things from them.
- Innocent World (EX Rank): A Skill that pronouncedly reflects the imagery created by humanity's fear of death and disease. Since said images are so miscellaneous, mixed and disorganized, they get simplified when recalled, and their nature varies for each person brought into the underworld created by the Noble Phantasm.
- Guidance of the Underworld (EX Rank): The Skill of granting a variety of divine blessings to those it regards as allies, among the ones brought into the territory turned into a Underworld by its Noble Phantasm. Since Pale Rider is not really a King of the Underworld, this Skill is slightly different from the Protection of the Underworld Skill that one goddess has.
 Fate/strange Fake - Volume 6 - Servant status: Rider[T]
Master: Kuruoka Tsubaki
True Name: Pale Rider
Sex: The concept does not apply
Height and Weight: Varies based on infection and diffusion (roughly equivalent to a parvovirus at minimum)
Alignment: True Neutral
Noble Phantasm: EX
■ Anti-Magic: C
■ Riding: EX
■ Infection: A
The ability to expand its territory by infecting other organisms with parts of itself in the form of bacteria or viruses. The minds and bodies of the infected are under Pale Rider’s control, and their minds are drawn into the world created by its Noble Phantasm. Their magical energy may sometimes be absorbed as well.
■ Innocent World: EX
A skill that reflects conceptions produced by human fears of “death” and “pestilence.” Because these conceptions are so varied, Pale Rider is a nondescript entity when it is first summoned and the tendencies of its very being change depending on those it draws into the “underworld” of its Noble Phantasm.
■ Guidance of the Underworld: EX
The ability to grant a variety of blessings to allies that Pale Rider has drawn into the territory that has become an underworld due to its Noble Phantasm. Because Pale Rider is not itself the ruler of the underworld, this skill differs slightly from a certain deity’s “Protection of the Underworld” skill.
■ Doomsday Come: Come, Dark Path, Come
Type: Anti-World Noble Phantasm
Maximum Targets: —
A Noble Phantasm that creates a Bounded World that becomes an artificial “underworld” with Pale Rider’s Master as its starting point, which acts as a receptacle for the “deaths” that Pale Rider bestows. Because it is strongly influenced by the Master’s conceptions, it can become an archetypal heaven or hell, but it can also become a space that acts as absolute nothingness and destroys souls. In extreme circumstances, Pale Rider can pull its target’s body into the ward as well as their mind. The ward is typically smaller in scale, but as a result of connecting to the land itself and other factors, Pale Rider is currently creating a larger ward than it would when summoned normally.
■ Kagome Kagome: Sword, Famine, Death, Beast
Type: Anti-Army Noble Phantasm
Maximum Targets: 999
The ability to manifest and utilize the power of numerous objects that impart “death” to others within Pale Rider’s ward. In an ideal environment, it is also capable of recreating a mythical “doomsday” to the extent that magical energy will permit. It did not reach that level because Tsubaki lacks knowledge of the Apocalypse or Ragnarök and did not wish for a hell. The pronunciation of this Noble Phantasm’s name varies from Master to Master.
- Fate/strange Fake Volume 1 - Prologue V: "Rider"
- Fate/strange Fake Volume 1 - Chapter 1: "The War Begins"
- Fate/strange Fake Volume 4 - Chapter 11: Day 2, Morning "The Gods Return From Twilight"
- Fate/strange Fake Volume 3 - Chapter 9: Day 1, Evening "A Horse Not Yet Pale; Mud Yet Firm"
- Fate/strange Fake Volume 4 - Chapter 13: Day 2, Night "At Last, a Second, and a Third..."
- Fate/strange Fake Volume 5 - Interlude: "Mercenary, Assassin, Vampire II"
- Fate/strange Fake Volume 6 - Bridge: “Canon of the Demigods, Act 2”
- Fate/strange Fake Volume 5 - Interlude: "Mercenary, Assassin, "
- Fate/strange Fake Volume 6 - Interlude: “A Beauty and the Sea; A Girl and a Mercenary”
- Fate/strange Fake Volume 6 - Interlude: “A Mercenary is a Free Man II”
- Fate/strange Fake Volume 6 - Interlude: "Mercenary, Assassin, Pale Rider"
- Fate/strange Fake Volume 6 - Chapter 18: “As Dream and Reality are Both Illusion I”
- Fate/strange Fake Volume 6 - Chapter 19: “As Dream and Reality are Both Illusion II”
- Fate/strange Fake Volume 6 - Chapter 20: “Fantasy Becomes Reality”
- Fate/strange Fake Volume 2 - Chapter 2: Day 0, Midnight "The Heroic Spirit Incident"
- Fate/strange Fake Volume 4 - Chapter 10: Day 2 “Separate Mornings, Separate Pasts I”
- Fate/strange Fake Volume 3 - Chapter 8: Day 1, Afternoon (2) "The Wandering King's Rock'n'Roll"
- Fate/strange Fake Volume 2 - Chapter 6: Day 1, Noon "Two Archers and..."
- Fate/strange Fake Volume 3 - Chapter 7: Day 1, Afternoon (1) "The Canon of the Demigods"
- Fate/strange Fake Volume 5 - Chapter 14: “Gold and Lions, Part 1”