Chapter Summaries

Su Yang’s long-dormant God-Tier Sign-In System finally began activating after more than ten years of absorbing energy. Meanwhile, Sona Sitri considered making him her Devil Servant and planned to seek Ajuka’s help, while Su Yang left Kuoh Academy unaware of her intentions.

• Su Yang finished reading in the Student Council room and said goodbye to Sona Sitri as the school closed.
• Tsubaki Shinra asked whether Sona Sitri planned to make Su Yang her Servant, and Sona praised his intelligence, chess skill, and abilities.
• Sona Sitri considered asking Ajuka for his Magic Formula and programs to help Su Yang, despite Tsubaki Shinra warning that it could affect her sister’s reputation.
• Su Yang left the teaching building and learned that his God-Tier Sign-In System had activated at 0.001% after absorbing energy for more than ten years.

After a year in Sona Sitri’s Student Council, Su Yang activated his system and received a King-level sign-in challenge at Ophis’s location. He worked out where she might be within reach of Kuoh Academy and headed to a clock tower to search the area.

• Su Yang explained that he had joined Sona Sitri’s Student Council instead of Rias’s Occult Research Club because he believed Sona valued ability more than innate talent.
• After a year in the Student Council, Su Yang activated the God-Tier Sign-In System and triggered a King-level sign-in at Infinite Dragon God Ophis’s head, with a one-hour time limit.
• Su Yang questioned how he could reach Ophis safely, and the system assured him that the location was somewhere he could reach before the deadline.
• Su Yang calculated that he could travel about fifteen kilometers from Kuoh Academy in an hour and used his memory and computational ability to map the nearby area.
• Su Yang ran to the top of a clock tower and calculated locations where Ophis might appear.

Su Yang found Ophis at an arcade, where she was longing for a panda plush in a claw machine. He won it for her, and Ophis asked what reward he wanted in return.

• Su Yang spotted Ophis staring at a claw machine and went over to it.
• Su Yang used a token and shook the machine so the panda plush fell into the prize chute.
• Su Yang gave the panda plush to Ophis, who eagerly took it.
• Ophis asked Su Yang what he wanted as a reward for his offering.

Su Yang patted Ophis's head and gained the Ten Avatars of Vishnu, whose fusion caused powerful manifestations across the world. The avatars vanished into Su Yang, leaving the supernatural factions wondering who had gained such power.

• Su Yang patted Ophis's head and triggered a King-tier sign-in at Ophis's head.
• Su Yang received the Ten Avatars of Vishnu, and their power began fusing with him.
• The Fish Avatar and then the other nine avatars appeared over the Far East Islands, alarming supernatural beings around the world.
• Shiva questioned Vishnu about the manifestation, but Vishnu denied that it was his power.
• Sirzechs asked Ajuka if he could locate the source of the power.

Su Yang completed the fusion of Vishnu’s Origin and gained immense power, drawing the attention of pantheons worldwide to Japan. Ophis asked him to help reclaim Original Peace, but when someone approached, Su Yang vanished before he could explain what he wanted.

• Ajuka and pantheons around the world traced the strange phenomenon to Japan, near Kuoh Town.
• Su Yang completed the fusion of the Hakoniwa Origin Vishnu Incarnation and sensed the power of Vishnu’s Ten Great Incarnations within him.
• Ophis asked Su Yang to help her reclaim Original Peace and offered to fulfill his wishes.
• Su Yang explained that his body was still too weak to wield the incarnations’ full power, then agreed to help Ophis if she helped him.
• After sensing a spatial fluctuation, Su Yang activated Vamana’s incarnation and disappeared, leaving Ophis watching in the direction he went.

Cao Cao and Georg found Ophis and took her back to The Khaos Brigade’s base, while Su Yang returned home to test his new powers. A sign-in notification then appeared, giving him three hours to sign in at Koneko’s Cat Tail.

• Georg located Ophis, and Cao Cao told her to return to their usual place.
• Ophis recalled the boy she had met and decided to wait for him to grow stronger.
• Cao Cao led Ophis and Georg back to The Khaos Brigade’s base, excited by the possibility of facing powerful Avatars.
• Su Yang returned home and prepared to test the powers he had gained from the Ten Great Incarnations.
• Su Yang heard a knock at the door as his system announced a Silver-level sign-in at Koneko’s Cat Tail.

Su Yang delivered Issei Hyoudou the BL game he had requested and then used a magical flyer linked to Rias's Peerage. He chose to summon Koneko.

• Issei Hyoudou visited Su Yang, who gave him the BL game Blue Sky, also known as Male Beauty Sky.
• Su Yang warned Issei to keep his interest quiet until he could handle society's judgment, while Issei said he was hiding it at school.
• After Issei left, Su Yang went to the mall and returned with a magical flyer that could summon a member of Rias's Peerage.
• Su Yang prepared to use the flyer to summon Koneko.

Su Yang summoned Koneko Toujou through a request for a gaming companion, and the two played a fighting game at his home. Koneko lost repeatedly and left determined to challenge him again.

• Rias sent Koneko Toujou to fulfill Su Yang's request for a gaming companion and told her to hit him if he harassed her.
• Koneko arrived through the magic circle and sensed that Su Yang seemed different from before.
• Su Yang and Koneko began playing a fighting game, and Su Yang defeated her repeatedly for half an hour.
• Su Yang suggested they play again another time, while Koneko resolved to ask Akeno to deal with his teasing.

Su Yang commissioned Koneko to wear a catgirl outfit and give him a princess carry, prompting her to confront her discomfort with her Nekomata identity. The chapter ended when Koneko’s sister Toujou Kuroka appeared inside Su Yang’s domain, and Su Yang complained that she was standing on his expensive roof beam.

• Koneko agreed to Su Yang’s commission despite recognizing that he was teasing her, because the offer was too generous to refuse.
• Su Yang showed Koneko a catgirl outfit, and she reluctantly put it on before giving him a princess carry.
• Su Yang told Koneko she could keep the outfit, and she accepted it before setting him down.
• Toujou Kuroka appeared nearby and teased Koneko about using her Nekomata power, startling Koneko because she had not sensed her sister’s arrival.
• Su Yang asked Toujou Kuroka to stop posing on his expensive roof beam.

Su Yang confronted Heige when she came to take Koneko away, and Koneko refused to leave with her. After Heige mocked Su Yang as a powerless human, he surprised her by stroking her sensitive cat ears and tail and obtained the Copycat Eyes through a sign-in.

• Heige revealed herself on a ceiling beam and told Koneko she had come to take her away.
• Koneko refused to go with Heige, and Su Yang said he would not hand over his junior.
• Heige mocked Su Yang as a powerless human and insisted Koneko should find a strong mate.
• Su Yang received sign-in notices for Heige's cat ears and the Golden Cudgel, then stroked Heige's ears and tail.
• Su Yang completed the sign-in at Heige's cat ears and fused with the Copycat Eyes.

Su Yang used the Copycat Eyes to understand Heige’s magic and prove he could protect Koneko by instantly carrying her away from the confrontation. He told Koneko that his unusual abilities came from a Heroic Bloodline, leaving her curious about what kind of Hero he was.

• Su Yang fused with the Copycat Eyes and learned the nature and weaknesses of Heige’s Magic Circles.
• Heige tried to recruit Su Yang and threatened that she could take Koneko away, while Koneko objected to her advances.
• Su Yang used Instant Movement to carry Koneko to a nearby clearing, avoiding a fight that might damage Heige’s home.
• Koneko wondered whether Su Yang had Maou-class strength, and he said his ability came from a Heroic Bloodline and that his strength was about the same as hers.
• Koneko asked what kind of Hero Su Yang was, and he promised to explain another time.

Su Yang carried the weakened Koneko toward her sister Heige, and touching Koneko’s exposed cat tail triggered a sign-in that granted him the incomplete Spirit Holy Sword Ester. When Heige confronted them, Su Yang summoned Rama’s Incarnation and launched a barrage of golden weapons at her.

• Su Yang set Koneko on his back, and her weakness caused her cat ears and tail to appear.
• Su Yang touched Koneko’s tail and received the incomplete Spirit Holy Sword Ester as a sign-in reward.
• Koneko sensed Heige approaching, and Su Yang reassured her while carrying her.
• Heige confronted Su Yang for taking her little sister without permission and unleashed Magic Circles.
• Su Yang merged with Rama’s Incarnation and attacked Heige with golden weapons, making her sense danger.

Su Yang fought Heige while trying to resolve her conflict with Koneko, then faced the Monkey King, who believed Su Yang was descended from a Hero. The Monkey King decided to help Heige take Koneko and leave the country, and prepared to attack Su Yang.

• Su Yang’s divine armaments broke through Heige’s defensive array and struck her, though she was not seriously hurt.
• Su Yang explained that he respected Koneko’s will and wanted to resolve the sisters’ conflict, which stemmed from Heige killing the Devil Master who had threatened Koneko.
• The Monkey King arrived and guessed that Su Yang was a Hero blessed by gods and Buddhas because of the armaments he used.
• Su Yang declined to reveal which Hero he might be descended from and offered to tell the Monkey King if he helped capture Heige.
• The Monkey King and Heige agreed to act quickly, and the Monkey King extended his Golden Cudgel.

Su Yang completed a sign-in on Monkey King's Golden Cudgel and received enhanced Chains of Heaven while resisting Monkey King and Heige's attempt to take Koneko. Serafall and Sona arrived to stop them, and as Heige prepared escape magic, Su Yang remained too depleted to help.

• Su Yang blocked Monkey King's Golden Cudgel, dispelled Heige's Magic Circle, and completed his sign-in, earning the enhanced Chains of Heaven.
• Heige accused Su Yang of taking someone else's little sister, but he chose not to bind her with his new reward.
• Serafall descended and threatened Monkey King and Heige with powerful ice magic, while Sona asked her to capture them without excessive force.
• Monkey King and Heige decided to retreat, but Serafall tried to stop them as Heige produced escape Magic Circles.
• Su Yang did not disperse the escape magic because his Spiritual Power was nearly depleted.

Su Yang told Sona that he had awakened the power of a Hero and received a trove of magical knowledge from her. As Koneko was sent away to recover, Serafall triggered a new sign-in opportunity that left Su Yang considering its requirements.

• Su Yang thanked Sona and claimed his newly awakened Heroic power had brought memories of the supernatural world to his mind.
• Sona sent Koneko Toujou to Rias for further treatment, and Su Yang said goodbye to her.
• Sona gave Su Yang a Crystal Ball containing Ajuka's compiled magic knowledge.
• Serafall returned and joked with Sona about the people who had escaped, prompting Su Yang to trigger a Diamond-level sign-in plot involving Serafall's Demon King and Magical Girl cosplay game.
• Su Yang considered how he might complete the sign-in plot as Sona pinched Serafall's cheek.

Sona gave Su Yang a Crystal Ball containing magical lessons recorded by Maou Ajuka, whom she had asked to teach him. After returning home, Su Yang studied Ajuka’s first lesson and continued considering how to strengthen himself while retaining his human identity.

• Sona reassured Su Yang that devils were not evil and said she would explain more the next day before teleporting away with Serafall.
• Su Yang returned home using Vamana, the Dwarf and reflected on his need for greater Spiritual Power and physical strength.
• Su Yang considered becoming a devil for a rapid power increase but chose to keep his human identity and accepted that his body would grow stronger over time.
• Su Yang pressed the Crystal Ball’s red button and saw a phantom of Maou Ajuka, who introduced himself as Su Yang’s temporary teacher.
• Ajuka began teaching Su Yang how to construct a Magic Circle, and Su Yang quickly understood the lesson and pressed the button to advance.

Su Yang studied magical energy and quickly mastered the lessons until Serafall arrived late at night, claiming Sona had thrown her out. After he let her stay, Serafall asked how he had joined Sona’s Student Council despite not being one of her servants.

• Su Yang used his Copycat Eyes, Krishna’s authority, and his computational ability to quickly learn lessons about magical energy and magic circles.
• Serafall rang Su Yang’s doorbell in the middle of the night, and he let her into his home.
• Serafall said Sona no longer wanted her close and had kicked her out, so Su Yang offered her a place to stay.
• Serafall asked Su Yang how he had joined Sona’s Student Council when only Sona’s servants could join.

Serafall visited Su Yang and urged him to become Sona's devil Servant, explaining the sacrifice Sona had made to help him. Su Yang refused to give up his human identity, demonstrated that Serafall could not restrain him, and offered to return the Crystal Ball the next day.

• Serafall praised Su Yang for beating Sona at chess and brought up the item Sona had obtained for him from Ajuka.
• Serafall told Su Yang that Sona had made a promise as the Sitri family's next head for his sake, and Su Yang promised to repay Sona's kindness whenever she needed him.
• Serafall offered Su Yang a long lifespan, greater strength, and a place as Sona's devil Servant, but Su Yang refused to become a devil.
• Su Yang appeared beside Serafall and handled her Magic Wand, warning that she could not force him to join her side against Sona.
• Su Yang offered to return the Crystal Ball the next day after copying and memorizing Ajuka's knowledge.

Serafall tried to recruit Su Yang for Sona and, after he showed he could rapidly understand Ajuka’s teachings, decided to reincarnate him as a devil without his consent. She secretly began the reincarnation ritual in Su Yang’s room, where the first two Pawn pieces were consumed and the third produced no reaction.

• Su Yang passed through the restrictions on Ajuka’s lessons and said he had already learned about one-tenth of both the formations and their contents.
• Su Yang went to bed, leaving Serafall frustrated after she restrained herself from attacking him to avoid upsetting Sona.
• Serafall secretly took Sona’s unused Devil Chess Pieces and decided to make Su Yang a devil so she could bully him.
• Serafall entered Su Yang’s room at night and started the reincarnation ritual with a Pawn piece.
• The ritual consumed a second Pawn piece after another brief flare, but the third Pawn piece caused no reaction.

Su Yang woke after a night spent absorbing the Devil Chess Pieces Serafall had given him and discovered that Esther had slept beside him. He sent Esther into his Contract Emblem and headed out for school, where he sensed someone waiting outside his bedroom door.

• Serafall added several Devil Chess Pieces to Su Yang, including a Rook, hoping to turn him into a devil.
• The Sign-in System announced a Bronze sign-in at Kuoh Academy with a two-hour time limit, waking Su Yang at six o'clock.
• Su Yang found Esther hugging him in bed and remembered that he had drawn the Demon-Slaying Holy Sword the previous day.
• Esther recognized Su Yang as her master and transformed into white light, entering the Contract Emblem in his hand.
• Su Yang noticed his strength had increased and opened his bedroom door, sensing someone standing outside.