World Rejecter Arc

The World Rejecter Arc is a story arc in Shinyaku Toaru Majutsu no Index, covered in Shinyaku Toaru Majutsu no Index Volume 14. The story arc introduces Kamisato Kakeru, a "normal high school boy" who wields a right hand with a mysterious power that's different from Kamijou Touma's, and the consequences of their first formal encounter while dealing with two supernatural creatures that involve Patricia and Leivinia Birdway.

This arc directly follows the events of the Magic God Invasion Arc, occurring on the night after High Priest's rampage on Academy City.

Gremlin
In order to help regulate the distortions caused by their immense power and give them piece of mind, the true Gremlin had intended Kamijou Touma, bearer of the Imagine Breaker born from the wishes of all magicians (with the Magic Gods being the largest influence), to become their 'scorer'. However, the actions of Othinus and her interactions with Touma in November led them to have subconscious doubts regarding their chosen scorer. As Othinus was about to die in Denmark, the High Priest intervened to save her death, as it might have provoked a change in Touma undesirable to Gremlin.

After their Hidden World was compromised by Aleister Crowley, Gremlin decided to take action themselves and entered Academy City, however Aleister subverted the spell they used to safely enter the world and severely weakened them. Following this and the death of Zombie, on December 3rd, the High Priest personally approached Touma with the offer to become Gremlin's scorer. On being refused, he attempted to persuade him through destruction, leading to a destructive chase through the city with Touma fleeing the rampaging mummy on an acrobike with Misaka Mikoto. At the end of this rampage, the High Priest was shot into space by a mass driver and attempted to crash the Arrowhead Comet into Academy City but was killed by Kihara Noukan, channeling Aleister's hate-filled willpower through the Anti-Art Attachment, with explosion from the comet's destruction shattering all the glass in the city.

After the High Priest's death, Niang-Niang attempted to destroy the city to eliminate the threat to them but was suddenly attacked and exiled by Kamisato Kakeru, a boy with a special right hand, World Rejecter. The other Magic Gods met a similar fate and only Nephthys was able to escape being completely exiled, due to her separated organs. Mailing herself to Touma, Nephthys sought his help, pointing out that Othinus was also going to be in trouble.

World Rejecter
Due to the doubts which arose in the minds of the true Gremlin regarding Kamijou Touma, their subconscious wishes, with the majority of the Magic Side's power behind them, began to form a new power, World Rejecter. Formed from wishes to escape to a new world rather than cling to the current world, the World Rejecter is capable of exiling individuals with conflicting desires to excess regions in the world's timeline, as well as powers and constructs originating from them. The existence of this power wasn't known to the Magic Gods or even Aleister Crowley, though Laura Stuart was aware of it.

The World Rejecter manifested in the right hand of Kamisato Kakeru, an ordinary high school boy who lived an apparently ordinary life in an ordinary town outside of Academy City. Around the start of November, Kakeru and his life began to be affected by a strange influence, eventually leading to World Rejecter's full manifestation two or three days prior to December 3rd, around the time the Magic Gods descended into the world. In the short time in-between, Kakeru was involved in various incidents and saved over a hundred girls, becoming acquainted with the worlds of magic and science.

The rescued girls, including some of Kakeru's former friends and acquaintances, formed the Kamisato Faction around him. Disturbed by their dependence and affection towards him, something he believed shouldn't be directed towards an ordinary high school boy like himself, Kakeru began to believe that they had been changed by the World Rejecter, not believing at all that his own actions drew them to him. Hating that his power had apparently warped the girls into a harem, on finding out about the Magic Gods who had given him the power and believing it was a deliberate action, Kakeru decided to eliminate them in revenge. He also learned of the Imagine Breaker and decided to meet Touma, due to their apparently similar circumstances.

Sample Shoggoth
At some point between late November and early December, Patricia Birdway accompanied an Academy City sponsored research team to Antarctica, part of a study of changes in the ocean currents due to changing ice levels at the poles. While there, they encountered a parasite, later named Sample Shoggoth, which infested Patricia's body, consuming her fat and taking over its functions, putting her life at risk. Visiting different medical institutions for a way to deal with the parasite, Patricia eventually ended up in Academy City. The parasite was not a natural lifeform, speculated later by Kamisato Kakeru to be comprised of discolored Dark Matter and used in order to set a trap for him, due to his tendency for saving girls.

Around the same time, Leivinia Birdway desperately searched for a way to save her sister. Unable to find a solution with her cabal's methods, Leivinia left the Dawn-Colored Sunlight in order to find a way to cure Patricia's condition by herself. She eventually developed a hybrid method based on cannibalization and other elements from Africa, intending to have Patricia consume an organ she was growing inside her to replace the fat she'd lost and drive the parasite out. However due to Patricia's lack of knowledge concerning magic, Leivinia's reluctance to explain and the repercussions of a new organ being grown within the human body, she rejected the method out of fear for her sister's life and tried to stop her from going through with it.