Born as the son of Aeson, the king of Iolcos. His given name was Diomedes, but when he was taken by Chiron, his name was changed to Jason.
Jason argued with King PeliasWP, the usurper of his father's country IolcosWP, and eventually made him promise to return the country upon traveling far east to ColchisWP and returning with the Golden Fleece. The golden fleece was owned by King Aeetes of Colchis.
When Jason arrived in Colchis. Jason was supported by the Goddess Aphrodite, and upon realizing that the King of Colchis was unshakable, she decided to control the mind of his daughter Medea to help Jason. Medea was made to blindly love Jason, which resulted in her betraying her father and her country for a foreigner she had never seen. Her abilities allowed her to nullify her father's magic and the enchanted fire-breathing oxen, which gave Jason the chance to obtain the Golden Fleece.
King Aeetes was infuriated, and decided to personally lead his army to capture Jason before he left the country. Aphrodite once again used Medea to assist Jason's escape by forcing her to kill her own brother, Apsyrtus. While she only knew Jason by name, her forced love caused her to board his ship, the ArgoWP, and slice her brother into pieces right before the eyes of her pursing father. The King, overcome by grief, ordered for the collection of the pieces of his dead son, which allowed for the opportunity for the Argo to escape its pursuers.
After that, Medea, in order to let her beloved Jason sit on the throne, continued to murder any opposition with magic and strategy, but her practices disgusted Jason and caused him to gradually become adverse to her. Eventually, Jason switched his interests to another woman, going so far as to have children, which Medea could not forgive. She murdered his new wife and children with magecraft, the brokenhearted Jason undergoing a miserable last moment as he was crushed by the dilapidated Argo.
In Fate/Grand Order, Jason has the appearance of a young man with blond hair. In the anime adaption of Fate/Stay Night, however, Jason has dark hair.
Eh, I'm a Saber? Not a Lancer or a Rider?
With his overflowing confidence, placidness, and dignity as a king, he could have been a mostly benevolent ruler. But since he couldn't become king, his confidence turned to arrogance, and his placidness shifted into complacency. Save for a few exceptions, his treatment of his subordinates is extremely sloppy. But once he has his back against the wall, his instincts sharpen, and his commands become precise and accurate.
A comment from an Argo crewmate: "Why does he suck so much when he's not cornered?"
His relationship with his Master is more bad than good. He's boastful and incompatible with most kinds of people. On rare occasions, he can find a Master he's compatible with him, but when he does, it's when they are in the predicament of their lives. Situations where he doesn't even have the time to say "I ask you, are you my Master?". He'll run screeching and covered in sweat... and after a few laps he'll come up with some plan for a comeback.
Jason's greatest skill is his charisma. A natural-born leader, Jason is even capable of convincing Heracles as a Berserker to follow his commands. Indeed, in spite of lacking any genuine combat abilities, Jason was able to lead the Argonauts through his words alone.
Jason is a fan of Heracles. He does not take Heracles's defeat, or defeat in general, very well. While some people consider him "useless," and Medea has justifiable reasons for hating him, Jason is a man with good intentions. He simply acts rudely and mercilessly towards anyone who stands in his way.
Jason believes that humans are fundamentally brainless. The fools choose a fool to lead them and act the king, so the country is never at rest, wars break out, and the people starve. That is why Jason believes someone like him has to be the one to seize power. The country Jason seeks to make is one where every citizen can have an education. Of course, they'll never equal his wisdom, so he'll have to compensate for what they lack. As long as everyone obeys him, he'll give them suitable compensation and a prosperous land. A land where everyone feels safe, a land where no one will look at someone monstrous like Heracles and be afraid.
Third Singularity: Okeanos
Jason is summoned along with his fellow Argonauts: Medea, Heracles, and Atalanta. He is convinced by Medea per Solomon's instructions that sacrificing a god to the Ark would give him absolute power. After being told this, Jason ordered the other Argonauts to find the Ark and a god to sacrifice with exception of Atalanta who left. During their search they met Hector, who, unbeknownst to Jason, serves Solomon like Medea Lily. At some point he had Hector install himself as a double agent in Blackbeard's crew in order to capture Euryale.
Later, Jason retrieves a report from Medea that Hector has Euryale. He says they’ll search for the Ark once Hector returns. Medea suspects she’ll get an oracle of its location once he returns, which upsets Jason that she’s the only one can receive oracles. Regardless, he believes in her oracles, and himself as captain. He agrees with Medea that Chaldea cannot different the likes of the Argonauts, praising her magic and Heracles’s strength. Perturbed at Atalanta rejecting his invitation, he suspects she’s dead now, believing it’s deserved. He then orders the Argo to set sail to rendezvous with Hector.
Reaching Hector’s position, Jason launches a boulder at the Golden Hind. He surprised to see Asterios barely catch him, and wonders if he’s a werebeast. After hearing about his legend as the Minotaur, Jason merely mocks the group for lacking talent. He then threatens to have Heracles kill the group if they refuse to hand over Euryale. They refuse, so he sends Medea and Heracles to kill them. After the group kills Heracles once, Jason explains he’ll keep resurrecting until he’s killed eleven times. He is then given the Holy Grail by Hector. He then orders Heracles to kill the group, but Heracles goes after Eurayle instead. Asterios protects her from him. When Heracles ignores his orders to not kill her, Jason orders Hector to use his Noble Phantasm. After Hector’s spear impales the two Berserkers, Jason orders Heracles to capture Euryale once he resurrects. Hector however points out Asterios is still alive and is using the spear to keep a hold on Heracles. Jason orders him to go after them, but Asterios has already plunged himself and Heracles into the ocean. Angered the group will be gone by the time Heracles returns, he orders Medea to track them down. He is delighted that she already analyzed their magic circuits to track them, and they will find the Ark for them.
The Argonauts eventually locate the group. Jason orders the others to land on the island and seize both Euryale and the Ark when Chaldea's allied Archers launch their Noble Phantasms at him. In response, he orders Hector to protect, and Heracles to kill the Archers. Later, Medea tells him Heracles is dead to his disbelief. He refuses to believe it further that Chaldea killed Heracles when Francis Drake confirms what Medea said. He then orders a retreat.
The Golden Hind eventually catches up to the Argo, to Jason’s utter disbelief. Jason then uses the Grail to summon a Shadow Servant to kill the group. After it’s killed, he orders Hector to kill the group. He panics when Hector is killed, and wonders why Medea is smiling in their current situation. David then tells him that sacrificing a Divine Spirit to the Ark will cause the era to be destroyed. Confused by this, Jason asks Medea if David is lying, saying he was told sacrificing a Divine Spirit to the Ark would grant him power and invincibility. Medea answers the world’s destruction would technically make him invincible. Angered at being deceived, Jason states how he could finally create an ideal nation, a true utopia. Medea refutes his intentions and tells him he’ll never be an ideal king because his soul is hopelessly twisted. Infuriated by her words, Jason demands to know how he’s unqualified to be king since he built the Argo and gathered a crew of heroes. Medea then uses the Grail to incarnate him into Forneus, claiming it as her way of protecting him.
After Forneus and Medea are defeated, Jason is returned to normal, and demands Medea heal him. However, she cannot heal him as she herself will soon perish. Medea reveals she possesses memories of him deceiving and betraying her despite her adoration. She calls him both cruel and innocent and states that despite being weak, he attracts others to loyally serve him. She continues that since he betrays too quickly, it would be better for him to sink with the world to avoid any betrayal. Jason disappears in rage at her betrayal.
Event: Lady Reines's Case Files
He makes a brief appearance near the end of the recreation of Ritsuka's memory of the Third Singularity, objecting to the presence of Medea, who replaced her younger self in this fabrication. Equally unhappy with her circumstances, Medea brings an end to their hateful if comedic bickering by ending Jason herself. She celebrates being able to "finally [do] it!" as an uncomfortable Heracles looks on before they both vanish as well.
Atlantis: Ocean in the Age of Titans
Jason make a reapperance when he and the Argonauts are summoned by the Counter Force to establish a beachhead for Chaldea's arrival. At some point during this time, The Argo comes under attack from Artemis. Heracles sacrifices himself to ensure that Jason and the Argo survive knowing that only Jason has the right charisma and ocean combat experience to help Chaldea. He will eventually reward this faith by redeming his past actions with his role during this Lostbelt.
Eventually, Chadea's forces arrive and Jason joins up with Chaldea's master, in assisting with countering Odysseus's forces and using the Argo to travel around the Lostbelt. During this time he forms the Neo Argonauts with Super Orion, Mandricardo, Charlotte Corday, Achilles, Paris, Mochizuki Chiyome, and Bartholomew Roberts. He is critical as the Battle Commander for the Chaldean Forces during the final battle against Odysseus. He sacrifices himself to assist in delaying Odysseus after revealing that he had been critically wounded during the Argo's escape from Artemis and was barely hanging on. Medea had cast an illusion to make him seem normal and healthy to not drop morale.
In the Studio DeenWP anime adaptation of Fate/stay night, Jason was seen in Caster's flashback where he was marrying CreusaWP which later breaks Medea's heart as she was seen crying. Jason also makes a brief appearance in the first season anime adaptation of Fate/stay night [Unlimited Blade Works], as Shirou Emiya was heading towards Ryuudou Temple controlled by Caster, he is briefly seen holding the Golden Fleece.
In Fate/Apocrypha, it is mentioned that a remnant of the Argo is a catalyst that would be able to summon Jason and various other Greek heroes who sailed on the ship. In the manga adaptation, he appears in a flashback when Achilles recalls Chiron's other students.
The ~turas réalta~ manga adaptation specifies that he was summoned to Okeanos by Lev Lainur Flauros, who reveals Medea's deception to him after Heracles' defeat. Lev mocks Jason's dream and Heracles' status as the strongest Hero, enraging Jason to the point of trying to slay him, only for Medea to stab him in the back and force his transformation into a Demon Pillar.
Jason is mentioned to be one of the ten Servants who can be summoned by the Player in the prototype of Fate/strange Fake. Jason also appears in the shared dream of Bazdilot Cordelion, the Master of True Archer, that is a memory of his Servant. In the dream, Jason claims that he will become the greatest king, who will create the best and fairest nation, where even someone like Heracles, can live without worry. After he wakes up, Bazdilot talks about the dream with True Archer, calling Jason a fool. Although True Archer agrees, he tells Bazdilot to not treat Jason badly, as Jason was one of the few people that considered him a friend.
Jason is said to be weak to the point where it is possible to not even count him as an enemy, described by Atalanta as a "useless person". While he can be described as the "monster who organized the Argonauts" with only his eloquence and charisma, his power in battle does not amount to anything.
As a fighter, Jason's skills with the sword are mediocre despite his past training with Chiron, though they are manageable enough to allow him to hold his own for a bit but nothing more. However, Jason's true power lies in his charisma and ability as a leader, having been the one to gather numerous Greek heroes under his leadership including the famous hero Heracles, who even listens to his commands even while summoned as a Berserker.
- Riding (B Rank): Talent for riding. Can ride most mounts better than most people but can't mount beasts on the ranks of demonic beasts or holy beasts.
- Magic Resistance (B Rank): Negates magecraft with three or fewer verses on their activation. It's difficult to harm him even with Greater Magecraft or Ritual Curses.
- The Sought-After Golden Fleece (-): A fleece made of golden wool that he obtained at the end of his adventure. Relatively comforting and pleasant.
- Epiphany in the Jaws of Death (A Rank): When he gets into a scrape, he can escape with seemingly self-sacrificing moves. He's unsurpassable went it comes to getting epiphanies at the jaws of death. However, Jason strongly hates this ability. After all, he has to go through a life-threatening situation every time he needs a flash of inspiration.
- The Far Off Sea Route Conquered with Companions (B++ Rank): He pumps those who once boarded the Argo full of courage. Those who never did vaguely feel somewhat encouraged. Consider it a super-limited variant of Charisma's abilities.
Jason possesses Klironomia nanomachines, although he didn't implemented himself with nanomachines, he used it to turn Golden Hind into Argo. Medea gave him an ability to cover up his own wounds, letting other see that he is fine when he is not.
In the Studio DeenWP adaptation of Fate/stay night, Jason had the appearance of a middle aged bearded man.
For the first version of his NPC design, I did a mean-faced loser, but I got told to make him hot, so I updated the design into something more good looking. To my complete surprise, he was later chosen to become a Servant, so I gave him a design themed after many different 80's rockstars. I love myself hilariously uncool guys. Also, he has a lot facial expression, just like Gof. - BLACK
- Fate/Grand Order material IX: Jason's Profile - Translated by ComunCoutinho
 Fate/Apocrypha material - Encyclopedia: Archer of “Black” [Servant], p.159-160 [T]
Archer of “Black” [Servant]
One of the Servants of the Black camp. His true name is Chiron. He is a centaur—a half-human-half-horse race, and he is a famous great sage in Greek myth.
He has a calm and gentle personality, but though he treats his Master with respect, he won’t hold back on advice if it’s for the sake of his Master. He never scorns or despises others regardless of whether they are enemy or ally, and he is exceptionally calm among the intense and passionate heroes of Greek myth. He acted as the strategist of the Black camp and continued to support his camp day and night right until he took part in the final battle.
Usually, centaurs are considered both as great huntsmen who effortlessly use bows and arrows while running with their horse legs and as savage monsters who would steal anything and everything. It seems Chiron alone is regarded as a “sage” that stands out as an exception among them.
Chiron was born from Cronus, father of the head god Zeus, and Philyra, the goddess of a certain island. However, because Cronus had copulated with her while she was turned her into a horse, Chiron was born as a half-human-half-horse centaur. (There is also the theory that they were attacked by Cronus’ wife Rhea while they were in the middle of copulating and Philyra turned into a stallion in order to run away.) Balking at the idea of giving milk to a monster like Chiron, Philyra changed her form into that of a linden tree.
Though he was never loved by his mother and father, Chiron became a sage that excelled in all forms of knowledge as he grew up. This is not necessarily unrelated to the fact that his mother’s name “Philyra” means linden tree. The leaves of linden trees can be used as restoratives, and the tree bark can be used in divination or as written boards.
After becoming an adult, Chiron began to rear the “future heroes” who implored for his tutelage from all over Greece. Besides Heracles and Achilles, the heroes who received his teaching include those like Asclepius, who later became the god of medicine, and Castor, who was sublimated as the Gemini constellation. Jason, the leader of the Argonauts who enticed Medea, is also one of his students.
On a certain day, someone shot a poison arrow at him while trying to stop a dispute between centaurs, and the poison continued to endlessly make him suffer due to his immortality, until he became the Sagittarius constellation by returning his immortality to the gods and finally received salvation. His wish for the Holy Grail while participating in the Holy Grail War is to regain his immortality. To him, it is the only gift he received from his parents.
As a Servant, his stats have received a slight rank down due to giving up his immortality and transforming his legs into those of a human, but even then he boasts of specks high enough for him to be called a first-rate Servant—to an extremely abnormal extent in a certain sense. In the first place, it appears that he taught not only swordsmanship, archery and horse-riding, but also wrestling techniques, so he is relatively experienced in moving with human feet.
With the combined effects of his skills, he can even utilize a pseudo-form of future sight, making him truly all-purpose in his abilities. If he has a weakness, it is that he lacks a decisive trump card. Against the brute force approach that throws away all wisdom or intelligence, his strong points fade away.
He deeply loves how weak and insufficient humans struggle despite their insufficiency and still try to move forward, so even if he was summoned as part of the Red camp, he would have definitely rebelled against them with the resolve to die.
Though if he were to describe it himself, he would merely answer, “This is my arrogance as a teacher, as embarrassing as it is”.
In the novels, he was mainly focused on his fight with Achilles outside of his light skirmish with Mordred. After all, Chiron was the only one capable of harming Achilles. That battle was such a great joy to him that he even forgot his true nature as a Servant, but he stood back up as a Servant again at the moment of his death and accurately dealt a fatal wound to Achilles.
 Fate/complete material III: World Material - The Servants of the Fifth Holy Grail War: Caster, p.030-031 [T]
Master: Souichirou Kuzuki
Alignment: Neutral Evil
Noble Phantasm: C
Medea, the daughter of King Aeëtes of Colchis in Greece, was a priestess taught by Hecate, the goddess of witchcraft. While she was raised without any discomfort, her fate was shaken greatly by the arrival of the ship Argo that sought the Golden Fleece.
Having fallen under the goddess Aphrodite's curse to fall in love with Jason, the Argo's captain, Medea stole the Golden Fleece from her father and attempted to flee the country together with Jason. Furthermore, to stall her father's ship that had been following them, she violently tore her brother to pieces and scattered his remains in the sea. With this, Medea lost a home she could return to, and came to be despised as a "witch" by the people. After that, Medea, in order to let her beloved Jason sit on the throne, continued to murder any opposition with magic and strategy, but her practices disgusted Jason and caused him to gradually become adverse to her. Eventually, Jason switched his interests to another woman, going so far as to have children, which Medea could not forgive. She murdered his new wife and children with magecraft, the brokenhearted Jason undergoing a miserable last moment.
Thus, Medea's obsessiveness and cruelty made calling her a "witch" appropriate, but despite committing inhuman deeds, she herself received no reward from this. Theories have been left behind that Medea, who achieved an immortal body from her devotion to the study of magecraft, became the reigning queen of the paradise, Elysium.
Having mastered magecraft from the Age of the Gods, Medea possessed extraordinary power as a magus. However, because her physical ability as a Servant was the lowest, she was at a disadvantage in battles against Servants with high Magic Resistance. Consequently, she faced the battles with basic tactics, avoiding personal combat to the best of her ability and using her Dragon Tooth Warriors as pawns. Even in combination with Kuzuki, he was the attacker and she bore the role of support with magecraft. She laid out a stratagem to summon Servant Assassin (Sasaki Kojirou) and order him to guard the Ryuudou temple gate while she gathered mana and used her own Noble Phantasm to destroy the other Servants' contracts and make them her allies.
Territory Creation: A
The ability to create a territory to gather mana is a special characteristic of the Caster class. Medea's inherent magical capacity is not that great but by expanding her territory to collect mana, it becomes possible for her to use high level magecraft. Moreover, because the place Medea selected to establish her territory is the underground limestone cave where the Greater Grail was instituted, Fuyuki City's greatest holy ground Ryuudou Temple, it is possible to gather an enormous amount of mana in a short time. She secured Ryuudou Temple as her main base solely to reserve enough mana to get Artoria and EMIYA to obey her after using "Rule Breaker" having summoning Servant Assassin independently. Furthermore, the influence of her created territory extends not only to Ryuudou Temple but also its surroundings. The rapid breakdown in the health of those inhabiting the periphery of the territory was because their life force was plundered for magical energy.
Because she understood the importance of the Ryuudou Temple territory the best, Sasaki Kojirou was ordered to guard the temple gate, and the interior was fortified so it could not be invaded easily. Furthermore, immediately following the beginning of the Holy Grail War, Medea almost never left the Ryuudou Temple, instead hiding on the grounds and raising mana. However, as soon as she made the judgment that she had collected enough magical energy for combat, she left the territory and turned on to the offensive.
Item Construction: A
Another skill granted to the Caster class. It is possible to construct enchanted tools, from implements of war to items for daily use. Many different articles can be made at will.
The dragon tooth warriors on the next page were made using this ability. In addition, it is also possible to make magical implements known as Mystic Codes. As Mystic Codes are used as devices to supplement thaumaturgy, or wielded as tools to activate specific effects during magical combat, this is a typical skill for a magus to possess. However, with an Item Construction rank of A, there is a great difference between the Mystic Codes that other magi build and the artifacts that Medea can create. Also, this skill requires time to gather components and manufacture items. This is why she spent most of her efforts on Territory Creation and focused on creating dragon tooth warriors. Though it requires preparation and planning, given enough time Item Construction has the potential to be a formidable asset.
High-Speed Divine Words: A
A skill that assists magical incantations. Normally, the length of an incantation increases with the scale of the thaumaturgy being performed, but this skill allows chants to be greatly abbreviated. It is particularly useful for direct attack magic. There are many examples of Medea personally using direct attack magic during the Holy Grail War, but in the fight against EMIYA she instantly unleashed countless blasts of light in an attack comparable to high thaumaturgy.
Caption: As long as a caster using High-Speed Divine Words has enough prana, she can continually fire powerful thaumaturgical attacks.
Golden Fleece: EX
The pelt of the golden-furred winged ram of Colchis. It contains the legend, "if thrown on the earth, a dragon will appear." Medea does not have the skill to summon the dragon, so she is unable to to do so even if she uses the Golden Fleece. This secret treasure might well have been the heart of the events that altered Medea's fate for the worse.
The Golden Fleece appears in Greek mythology, beginning with the marriage of King Athamas of Thessaly to his second wife Ino. Ino, who despised the children Athamas had with his first wife, the cloud goddess Nephele, plotted to kill the prince Phrixus by telling the king a false oracle and sacrificing the prince in a ritual. But then, Phrixus rescued his sister Helle at the altar. Helle rode a winged ram with golden fleece to safety, brought to her by Hermes, one of the Twelve Olympians. With the help of his sister, Phrixus went to Colchis, sacrificed the meat of the golden ram to Zeus, and offered its pelt to King Aeetes of Colchis. From then on, the Golden Fleece was passed down as a secret treasure of the royal house of Colchis.
Medea used many different types of magic during the Holy Grail War. Against nearby humans, she employed mind control, hypnosis, and other spells to gather intelligence and eliminate threats. She also used magic to lure Emiya Shirou into her own workshop.
In combat, she supported her Master Kuzuki Souichirou, who wielded the assassination technique "Snake." Souichirou, who seemed powerful enough to overwhelm a Servant, was actually being magically Reinforced to give him enough destructive power to damage a Servant.
Additionally, Medea used spatial teleportation whenever she was attacked. This spell was highly versatile.
Dragon Tooth Warriors
Magic that uses dragon teeth as foci to create golems. This is one of the magics Medea specialized in, passed down to the king of Colchis long ago. The combat strength of one dragon tooth soldier is no match for a Servant, and even a human Master can deal with one. However, they are dangerous in large numbers. Medea used these golems to buy time to advance her plans. The dragon tooth soldiers are not necessarily homogeneous in appearance, showing variations in the weapons they wield.
Type: Anti-Thaumaturgy Noble Phantasm
Range: 1 person
A Noble Phantasm with an ability clearly unlike that of the other Servants' Noble Phantasms. Its efficiency as a weapon is virtually nil, but it has the ability to "break" (as in, "violation of commandment" or "transgression of law") any magic on a target pierced by its blade. Targets that can be broken are contracts formed from prana, and life forms born from prana. Rule Breaker can reset the condition of the target to the state before magic was used on it. In other words, contracts formed from prana are wiped clean, and life forms created from prana are forcibly sublimated. Thus, its utility is quite limited, but it is extremely powerful within the context of the Servant system of the Holy Grail War.
In practice, Medea successfully used this Noble Phantasm to nullify the contracts between other Masters and their Servants. For a time, Artoria and EMIYA served Medea as her own Servants.
- Fate/strange Fake Volume 4 - Chapter 10: Day 2 "Separate Mornings, Separate Parts (Part 1)"
- Fate/Grand Order - Okeanos: The Four Sealed Seas of the End, Section 12: Defeat Heracles
- Fate/Grand Order - Okeanos: The Four Sealed Seas of the End, Section 14: Pioneer of the Stars
- Fate/Grand Order - Okeanos: The Four Sealed Seas of the End, Section 9: Track Down the Dandies
- Fate/Grand Order - Okeanos: The Four Sealed Seas of the End, Section 10: World's Oldest Pirate Ship
- Fate/Grand Order - Okeanos: The Four Sealed Seas of the End, Section 13: Betting It All
- Fate/stay night [Unlimited Bladeworks] - Episode 6: "Mirage"
- Fate/Apocrypha Manga - Chapter 52: "The Final Night"
- Fate/strange Fake Original Novel - Epilogue: Player
 Fate/Grand Order - And So The Ship Conquers
And So The Ship Conquers
A ship from the Age of Gods that carried many Heroic Spirits.
What lay at the end of its journey, victory or plunder?
Glory and ruin are like a gold coin spinning in the air.