Archer served Rin Tohsaka in the fifth Holy Grail War. He claims to have lost his memories but assures Rin that he is more than capable to serve as her Servant. Archer is very cynical and sarcastic but Rin discovered his habit of being extra critical to people he cares for. He occasionally shows a more naive side.
Archer has a sharpened sense of sight and his battle experience has honed his combat instincts. He is also skilled in a select few magic spells. As an Archer class, he is has minor resistance against magical attacks.
Archer is Shirou's future self. After winning the fifth Holy Grail War with Saber, he continued to improve his skills in order to become a hero of justice. Shirou worked as a freelance magus and as a vigilante. He continued to do what he thought was right, but he doesn't explain his actions to others. The general public did not understand him. He fought in and won a large battle but he was accused of being the one who started the war and was executed.
Shirou wanted to continue serving mankind, thus he made a pact with the will of the world to serve as a special type of Heroic Spirit, a Counter Guardian. Counter Guardians are humans that did not achieve legendary fame, but instead are humans who achieved considerable strengths and wished to serve as the world's peacekeepers. Counter Guardians are summoned every time a huge man-made calamity occurs. They are responsible for cleaning up the mess.
On February 1st, Rin summoned Archer. He claimed to have lost his memories and was unable to reveal his true name. Archer realized that Rin was about to enter her first Holy Grail War and was initially skeptical about her ability as a magus and a Master. After she consumed a Command Spell to bend him to her will, Archer praised her power and became more friendly to her.
In Archer's duel against Lancer, Lancer was surprised that Archer chose to fight in melee despite being an Archer class, and was confused when Archer could project multiple copies of his weapons even after being disarmed 27 times. Archer also managed to identify Lancer's true name.
After Rin revived Shirou and left her pendant behind, Archer gave her his pendant that looked exactly hers, claiming that he had picked it up earlier.
Later when Rin and Archer went to Shirou's home, he was shocked to see Saber again. She did not recognize him though and struck him down while he was incapacitated.
After Saber defeated Rider, Archer explained that Saber was willing to give her life to protect Shirou, and that Shirou could only accept her end.
When Saber, Rin, and Archer went to Einzbern castle to save Shirou, Archer stayed behind to fend Berserker off to allow the rest to escape. He advised Shirou to imagine a weapon that can defeat Berserker. Archer managed to take off 6 of Berserker's lives before he was killed.
Unlimited Blade Works
While Saber was dueling Berserker, Archer went to the top of a distant hill and fired Caladbolg II from his bow at Berserker. Shirou was angry because Archer risked damaging Saber but Archer explained that defeating Berserker is more important.
Archer took every opportunity to ridicule Shirou's ideal. Shirou and Saber were deeply affected by Archer's rants. He displayed intimate knowledge regarding Shirou. Archer also voiced his intention to win the war by any means necessary. He then tried to kill Shirou and Rin consumed a Command Spell to prevent Archer from harming Shirou.
Archer pressured Rin to defeat Shirou. After Caster obtained Saber, Archer betrayed Rin to side with Caster, claiming that Caster now has the highest chance to win the war. Later, Archer betrayed Caster in turn, explaining that his final goal was to kill Shirou and he needed Caster's Rule Breaker to escape from Rin's control. Archer attempted to kill Shirou again but Rin formed a contract with Saber and sent her to fight him off. He then kidnapped Rin and brought her to Einzbern castle, and demanded a duel with Shirou there.
At Einzbern castle, he explained that he is the future self of Shirou and that he had attained his dream to become a hero of justice. But as a Counter Guardian, Archer had witness the ugliness of mankind. He saw many people who wished harm on others. Archer had to kill some people to save others. He became disillusioned by his ideal.
Archer decided to kill Shirou in order to prevent Shirou from turning out to become him, thus erasing Archer from existence. Shirou managed to defeat Archer through sheer force of will, insisting that despite knowing what will happen, he has no regrets. Archer was reminded of his motivation that he had and while he was alive and he achieved enlightenment.
Gilgamesh then appeared to launch a shower of swords upon Shirou. Archer protected Shirou and explained that he was the only one left who could defeat Gilgamesh.
At Ryudou Temple, Archer appeared to help Rin and Shinji escape from the mass of flesh and helped Shirou escape from Gilgamesh. Archer was confident that Rin would keep Shirou in check and bade her farewell.
After Shirou discovered that Sakura was the Master of Rider, Archer reminded Shirou of his ideals.
After taking severe damage from the explosion cause by the black shadow, Archer requested that his arm be transplanted on to Shirou to save him. That operation saved Shirou as well as giving him access to Archer's abilities, knowledge, and power.
When Shirou was steeling himself to remove the magical red cloth to face Berserker, Archer appeared as a vision, giving Shirou the motivation to face his difficulties.
Archer is able to analyze the structure of an object and enhance the structural integrity of the object by imbuing the object with his magical energy. He is also able to boost the capability of a person's body by imbuing it with magical energy. Archer can also modify the shape of a weapon to better suit his fighting style.
Archer's projection creates an imitation of an object that he has analyzed.
After years of intensive training and the power he gained as a Heroic Spirit, he has attained the highest level of proficiency at projection speed, strength, and endurance.
Unlimited Blade Works
The source of Archer's magic. A Reality Marble is one of the highest level of magic and is considered as one of the greatest taboo in the world of magic. A Reality Marble is the inner world of the magus where the very laws and nature of the world is entirely dictated by the magus; as such the nature of a Reality Marble is unique to each magus. The magus can fully deploy a Reality Marble by projecting it on to the real world. It covers a small area and traps everyone within the boundary in the projected reality.
Unlimited Blade Works: Infinite Creation of Swords, is a vast desolate field full of swords that Archer has analyzed and weapons that he had collected throughout his lifetime. Within his Unlimited Blade Works, Archer doesn't need to project each sword individually. Instead, he simply wills it into his hands and he can will the swords to shower upon his target.
Archer does not have a signature weapon which could be identified as his Noble Phantasm. But if a Servant's signature ability is his Noble Phantasm, then Archer's Unlimited Blade Works would be his Noble Phantasm.
Late on the Unlimited Blade Works route, Archer learned to open a small instance of his Unlimited Blade Works to shower swords on his target, mimicking Gilgamesh's Gate of Babylon.
Kanshou and Bakuya
Archer's preferred swords that he discovered, remodeled, and added to his collection. Kanshou and Bakuya is designed with a Yin and Yang motif.
Archer first wielded them against Lancer in the Prologue. He was able to project multiple copies of the swords quickly and repeatedly. He also wielded them against Caster on the Unlimited Blade Works route.
Kanshou and Bakuya's special ability is to boomerang after it is thrown.
A bow that Archer created.
It is powerful enough to launch Noble Phantasm swords as arrows. His preferred arrow-sword is the Caladbolg II.
The bow is used twice on the Unlimited Blade Works route, once against Berserker and once against Caster.
A redesign of the Caladbolg which Archer remodeled to be used as an arrow.
The Caladbolg is a sword possessed by the Celtic hero Fergus. Cu Chulainn is destined to be defeated by Caladbolg due to a geas that he made.
Archer wielded it as a melee weapon in his duel against Shirou on the Unlimited Blade Works route.
Rho Aias is a magical shield that is shaped like a flower. It has 7 petals.
Archer obtained Rho Aias on his journey which he added to his collection.
Archer used Rho Aias in his second duel against Lancer on the Unlimited Blade Works route. Lancer's Gae Bolg managed to pierce all 7 petals and inflicted enough damage on Archer to knock him out without killing him.