Chapter Summaries

Merlin taught Yinsen a spell that could remove the impurities in his body and reshape it into a divine body, though the process could leave him much younger. After making plans for the lengthy treatment and informing Diana, Yinsen received a red crystal Merlin thought he might need.

• Merlin explained that his spell would crush and reconstruct Yinsen's body, potentially making him a child, and taught him how to cast it.
• Yinsen returned to the Moon Goddess, told the crew about his encounter and his plan to eliminate the hidden dangers in his body, and said he would first finish the teleportation arrangements.
• Yinsen contacted Diana, who worried over his aged appearance and asked what to expect during his treatment.
• Scáthach arrived through a portal and gave Yinsen a red crystal from Merlin.

Yinsen prepared Merlin’s Body Reshaping magic and destroyed his failing body so he could create a stronger one. As the spell began rebuilding him, he used its selection panel to choose the new body’s traits.

• Scáthach brought Yinsen a Dragon Blood Crystal from Merlin, and Yinsen recognized its powerful dragon essence as a valuable addition to the spell.
• Yinsen introduced Scáthach to the people aboard the Moon Goddess, while Diana teased him about finding Scáthach attractive and spent time getting to know Leah.
• Yinsen contacted The Ancient One and Tony, then let the ship’s crew gather to see his aged appearance before moving to the island to perform the magic.
• Yinsen drew the Magic Array beside Logan’s Wooden Cabin and warned everyone that the process might be frightening.
• The spell shattered Yinsen’s body into black ash while preserving his clothes and equipment, and a transparent Mental Body reassured Diana and Ada.
• Yinsen examined the spell’s panel and began selecting traits for his new body, insisting that it remain humanoid and male with black hair.

Yinsen used nearly all his stored magic power to reshape his body, leaving him with a youthful but powerful form and strange new abilities. He decided to remain with Diana and study his changed condition before traveling to other worlds.

• Yinsen spent his magic power to accelerate his body's growth and strengthen his divine form.
• The reshaping restored Yinsen's connection between his Mental Core, body, and soul, while his Mental Power Universe became a void containing only a Black Spot.
• Yinsen discovered that he could cast spells with ease, travel between planes instinctively, and create ordinary clothes by thought.
• Yinsen realized the crowd could see him naked, created clothes, and Diana teased him by kneading his cheeks.
• Yinsen told Diana he needed time to understand his new abilities, and she offered to stay and help test his body.

After gaining a divine body, Yinsen investigated his new powers, began adapting to his smaller form, and trained while teaching Leah and studying magic with Scáthach. As his body stabilized, he considered returning to Illya and sending Scáthach back, but she offered to stay and pursue independent magic.

• Yinsen built a Wooden Cabin near a hot spring by growing and shaping trees with magic, while Ada identified parts of the spell as Nature and Arcane Magic.
• Yinsen realized the energy in his body was divine power, while the Black Spot devoured energy directed into his Mental Power Universe and suggested a path toward creating it through a Big Bang.
• Yinsen trained with Diana to adapt to his smaller body, taught Leah magic, and helped Scáthach develop a magic system independent of the Root.
• Yinsen considered returning to Illya and sending Scáthach back once his body stabilized, but Scáthach offered to remain in exchange for Rune Magecraft and the Land of Shadows being free from the Root's restrictions.

Yinsen accepted Scáthach’s offer of energy from the Land of Shadows and discovered he could create and control physical energy clones. After testing the clones with Diana, he traveled with her and Scáthach to the Emiya Residence, intending to find Illya and collect his payment.

• Scáthach offered Yinsen the Land of Shadows’ vast energy in exchange for his help, and he agreed.
• Yinsen studied his body’s limits and realized he needed varied energy to fuel its growth, so he decided to collect energy from the Land of Shadows.
• Yinsen created three physical energy clones and controlled them simultaneously, but Diana quickly knocked them down during a test.
• Yinsen whispered a bold idea to Diana, who beat him until the clones dissolved back into energy.
• Yinsen invited Diana to accompany him and Scáthach, informed Logan and Banner of his destination, and teleported them to the Emiya Residence.

Yinsen returned to the Emiya Residence and found the surviving Servants living peacefully in the Present World. He revealed Artoria’s identity and challenged her to trust herself to save her Britain, leaving the others stunned by his claim that she was not dead.

• Yinsen arrived at the Emiya Residence with Scáthach and Diana, where Illya recognized him as Berserker and Shirou explained that Cú Chulainn was out working.
• Shirou told Yinsen that the Servants who remained in the Present World had settled into ordinary lives, while their Magic Circuits were gradually recovering.
• Yinsen revealed that Artoria was King Arthur, startling Shirou and Diana, and Artoria admitted she had been waiting for him to return.
• Yinsen explained that Artoria could save her own Britain herself, but Artoria said she did not believe she could do it.
• Yinsen asked whether Artoria would rather believe in the Holy Grail than in herself, then claimed she was not dead, shocking everyone.

Yinsen explained to Artoria, Shirou Emiya, and Illya how Parallel Worlds left their futures open, while assuring Artoria that Britain had prospered both with and without her rule. He offered to show her a world where King Arthur had led Britain to greater heights, then noticed that Sakura Matou and the others had brought enough ingredients for dinner.

• Yinsen bluntly told Artoria that she could have returned to Britain and restored order instead of doubting herself and giving up the throne.
• Yinsen used a stick-figure demonstration to explain that choices created Parallel Worlds, and that Shirou Emiya's future was not necessarily the future of Emiya.
• Artoria asked whether worlds existed where she had never become king, and Yinsen said Britain was doing well in those worlds too.
• Yinsen reassured Artoria that other worlds existed where King Arthur had made Britain powerful, and offered to take her to see one.
• Yinsen revealed that he had acquired ownership of the Type-Moon World and could summon Heroic Spirits from the Throne of Heroes.
• Sakura Matou arrived with ingredients, and Shirou Emiya suggested making hot pot for the guests.

After the Holy Grail War ended, Illya struggled to find a reason to live, so Yinsen and Diana suggested she experience ordinary life by going to school. Yinsen proposed a school where she could learn magic, leaving Illya to consider the idea.

• Yinsen introduced Diana as Zeus's daughter and explained that he had reshaped his body and become a True God.
• Shirou Emiya arranged rooms for the guests and left Illya alone with Yinsen and Diana.
• Illya admitted she no longer knew what she wanted after the Holy Grail War and her revenge goals had become meaningless.
• Yinsen explained that Kiritsugu had chosen his family in this world too, but learned the truth too late to save Illya.
• Diana suggested that Illya experience an ordinary person's life, and Yinsen proposed that she go to school to learn magic.

Yinsen observed Shirou Emiya practicing magecraft and swordsmanship while explaining that Illya was healthy after her transformation. Illya arrived at the dojo and dismissed Shirou’s basic training, suggesting he should study magecraft theory instead.

• Illya stayed up talking with Yinsen, then took his room to sleep while Yinsen prepared bedding for her.
• Yinsen found Shirou Emiya practicing magecraft, explained that the world’s rules still prevented spells from working, and assessed Shirou’s talent and flawed training.
• Yinsen reassured Shirou that Illya was healthy and had retained her enhanced physical qualities and magical talent.
• Shirou practiced swordsmanship with Artoria as Yinsen and Diana watched and discussed Artoria’s combat skill.
• Diana insisted on reaching godhood through her own strength, and Yinsen stopped pressing her before she punched him for patting her head.
• Illya arrived at the dojo and criticized Shirou’s basic training, saying he should learn more magecraft theory from her.

Sakura Matou and Medusa joined the group at the Emiya Residence, where Yinsen explained that the Holy Grail War had been destroyed and everyone learned more about the unusual people gathered there. As plans formed for a possible trip to another King Arthur's world, Soujun came to ask Yinsen to make him a Reincarnator, and Yinsen considered accepting him.

• Sakura Matou arrived to help Shirou Emiya prepare breakfast, and Yinsen startled her by asking about Medusa.
• Yinsen sensed Medusa nearby and invited her to enter through the front door; Medusa came in to protect Sakura Matou.
• Yinsen explained the changed circumstances and the end of the Holy Grail War, while Sakura Matou learned the identities and connections of the people at the Emiya Residence.
• The group discussed whether Shirou Emiya, Sakura Matou, and Rin Tohsaka would join Yinsen and Artoria on a trip to another King Arthur's world.
• Soujun visited Yinsen and asked to become his Reincarnator, explaining that he wanted to seize the opportunity; Yinsen considered cultivating him as a subordinate.

Yinsen offered Soujun a chance to become his Reincarnator, sending him to other worlds to retrieve unusual powers in exchange for possible rewards. After Soujun left to prepare and train, Yinsen found Illya and the others instructing Shirou Emiya, while Scáthach proposed they visit the Land of Shadows.

• Yinsen explained that he had no Reincarnation Space but could send Soujun to certain worlds in exchange for items and power samples.
• Yinsen told Soujun to train with Kojiro Sasaki, learn only the basics of Medea's magecraft, and plan a suitable first world.
• Yinsen gave Soujun a special item that would let him contact Yinsen and return from other worlds, and Soujun left excitedly.
• Yinsen found Illya, Scáthach, and the others training Shirou Emiya at the dojo, while Sakura Matou and Medusa watched.
• Scáthach suggested that she and Yinsen visit the Land of Shadows, then pointed out Diana's presence.

Yinsen brought Scáthach and Diana to the Land of Shadows, where Scáthach explained her plans to turn it into a source of magical power. Yinsen extracted a portion of its energy for himself and swallowed it, while the Land of Shadows remained intact for Scáthach to use.

• Yinsen used Teleportation Magic to take Scáthach and Diana from Shirou Emiya's dojo to the Land of Shadows.
• Diana learned that Scáthach had spent countless years alone in the desolate realm and reconsidered her objections to Scáthach staying aboard the Moon Goddess.
• Scáthach told Yinsen she planned to convert the Land of Shadows into a magical plane connected to herself and draw on its energy over time.
• Yinsen noted that the realm's laws over the dead interested him, but decided to extract energy first.
• Yinsen gathered a portion of the Land of Shadows' gray energy into an orb and swallowed it, saying it would take time to digest.

After confirming Artoria was the original, Yinsen brought the group to his spaceship to travel to Arthur’s Britain and invited Mordred to join them. Mordred arrived excited to go home, leaving Rin Tohsaka and the others stunned that she was a girl.

• Yinsen returned to the Emiya Residence with Scáthach, where Rin Tohsaka asked to study magic with him, and he announced that he would take everyone to Arthur’s Britain after dinner.
• Yinsen confirmed Artoria was not a duplicate and explained that the trip would help her face the other King Arthur and resolve her doubts.
• Yinsen used Teleportation Magic to take the group to the Moon Goddess, while Cú Chulainn arrived too late and found the residence empty.
• On the spaceship, Yinsen told Artoria that the other Arthur had asked him to train his child, Mordred, and Artoria learned she would meet a version of the child she had once killed.
• Mordred arrived in casual clothes, eagerly asked whether she was ready to inherit the throne, and the group reacted in shock to discovering she was a girl.

Yinsen brought Mordred, Galahad, and a group of visitors to Arthur’s Camelot, where Artoria encountered her counterpart and marveled at the city’s progress. After catching up with Arthur and hearing about his plans to unify the world, Yinsen revealed that Artoria was another world’s King Arthur and needed Arthur’s guidance.

• Yinsen used Planar Teleportation to bring Mordred, Galahad, Artoria, and the others to Camelot.
• Mordred reunited with Arthur, agreed to stay and see her mother, then hurried away to explore.
• Arthur greeted the visitors and recognized Yinsen despite his childlike appearance.
• Arthur told Yinsen about his reforms and his goal of unifying the world, though years of work had weakened him.
• Yinsen told Arthur that Artoria was King Arthur from another Parallel World and needed his guidance.

Yinsen settled into Camelot, made a soul-bound communication and teleportation tool for Soujun, and worked to absorb the energy needed to complete his transformation. He remained child-sized and decided Illya and Leah still needed to attend school, while Illya continued learning magic from him.

• Arthur assigned Gawain and Lancelot to show Yinsen’s companions around Camelot, giving Yinsen more time for his own work.
• Yinsen created a special tool for communication, positioning, and long-distance teleportation, then bound it to Soujun’s soul.
• Diana helped Arthur expand his territory before returning to Camelot to spend time with Scáthach.
• Yinsen found that his body and Mental Power Universe needed enormous amounts of energy, and he remained in the form of a child despite feeding energy into his body.
• Illya asked whether learning magic meant she could stop going to school, and Yinsen told her she still had to attend so she could have a more normal childhood.

Yinsen took Illya for a walk and found the others back from Camelot after Arthur summoned Gawain and Lancelot. As Rin Tohsaka planned to learn magic, Yinsen realized Shirou Emiya had gained skills through his connection with Emiya and decided he would need less training than expected.

• Yinsen thought about making people with unhappy childhoods attend school with Illya, but refused when she asked to skip it.
• Yinsen took Illya around the grounds, where they found the group had returned after Arthur summoned Gawain and Lancelot.
• Rin Tohsaka offered to help Arthur, but Emiya reminded her that she could not use Magecraft there and Illya pointed out that Shirou Emiya and Sakura Matou had been practicing.
• Shirou Emiya explained that he had learned magical techniques through dreams and his connection with Emiya, while Emiya had also learned to cast magic without relying on the Root.
• Yinsen realized Shirou Emiya had grown stronger and saw that Rin Tohsaka had latched onto him, prompting Diana to question his intentions.

As Arthur prepared to lead an expedition against suspicious northern pirates, Yinsen continued teaching magic in Camelot while the group decided who would stay or leave. Shirou Emiya and Sakura Matou chose to accompany Artoria, Rin Tohsaka planned to go with Yinsen, and Emiya prepared to return to his work until Yinsen offered him an unexpected reward.

• Arthur mobilized the Guard Knights after the northern pirates repeatedly evaded local forces, and Artoria planned to join his expedition.
• Yinsen taught Shirou Emiya, Rin Tohsaka, and Sakura Matou foundational magic while Shirou also studied cooking.
• Shirou decided to stay in Britain and go with Artoria, and Sakura chose to remain because Shirou was staying.
• Rin decided to accompany Yinsen to a different world's Magic School, while Emiya chose to return to his work safeguarding humanity.
• Yinsen told Emiya that he did not need to return to the empty place and called the offer a reward from his new boss.

Yinsen gave Emiya more rest and made Fuyuki his home between missions, then prepared to take Rin Tohsaka, Illya, and Leah to Hogwarts. As Diana planned to leave for Themyscira, Yinsen proved her assumption about his child-sized form wrong.

• Yinsen reduced Emiya’s workload to one mission a month and set Fuyuki as his place to rest between assignments.
• Yinsen returned to the Moon Goddess with his companions and sent Emiya back to the Type-Moon Universe.
• Yinsen planned to enroll himself, Illya, Leah, and Rin Tohsaka at Hogwarts, and offered Rin a potion to make her body eleven years old.
• Logan refused to become a child or attend school and arranged to stay with Diana on Themyscira.
• Diana planned to leave for Themyscira in a few days, but Yinsen overturned her expectations that his child-sized form would limit him.

Yinsen prepared to enter Hogwarts with several companions, arranging their identities and enrollment so they could attend alongside Harry Potter. Logan returned from Diana’s world and asked Yinsen for a potion so he could join them.

• Yinsen and Diana exchanged magically written words on each other before Diana returned to her world with Sherry and Laura.
• Yinsen learned that Illya, Leah, and Rin Tohsaka would attend Hogwarts with him, while Selene would act as their guardian.
• Scáthach revealed that she had altered Yinsen’s potion to become a little girl and insisted on joining the Hogwarts group.
• Yinsen added the children to Hogwarts’ new student registry and began creating convincing background records with Selene.
• Logan returned from Diana’s world, said Sherry and Laura were staying there, and asked Yinsen for a potion so he could attend Hogwarts too.

Logan asked Yinsen to make him a potion that would let him hide in another world from Queen Atlanna, who wanted him to stay in Atlantis. The potion turned him into a ten-year-old, and after learning why Logan was fleeing, Yinsen encouraged him to stand up for himself while teasing him about the consequences of his relationship.

• Yinsen gave Logan a potion that transformed him into a ten-year-old, then provided him with clothes and candy.
• Yinsen reminded Logan that time in other worlds passed differently, but Logan still decided to spend a few years away and grow up first.
• Logan told Yinsen that Queen Atlanna of Atlantis had wanted him to remain in Atlantis, so he left rather than let her override his wishes.
• Logan explained that he and Atlanna had grown close after he helped foil a conspiracy against her during a conflict between Atlantis and Themyscira.
• Yinsen told Logan he could keep seeing Atlanna if he truly liked her, then asked whether she had become pregnant.