Toaru Majutsu no Index Light Novel Volume 19/Chapter 4

Synopsis
As the only one conscious among the members of GROUP, Accelerator engages in conversation with the being who introduced itself as Aiwass. The Level 5, unable to grasp Aiwass' identity, thinks of defeating him to thwart Aleister's plan, however, the fact that he didn't amazed the mysterious being. Soon, Aiwass describes its existence as similar to Fuze = Kazakiri but not produced unlike her, and it once more asks Accelerator if he will attack in order to oppose Aleister. Although Aiwass itself is not enough to push him to take action, the mention of Last Order's safety under the circumstances of Aleister's plan was ultimately the trigger for the Level 5 to respond.

Shiage and Rikou are forcefully separated as Mugino Shizuri begins pursuing the former in a psychotic rampage while dragging Rikou along with her. Mugino continues to batter down on Shiage, forcing him out of hiding but not firing an attack that will surely kill him. Then, after using Rikou both as a shield and an source of frustration for Shiage, Mugino forces Rikou to use Body Crystal and provokes her into using AIM Stalker against her former comrade. Shiage responds to this by using a crane to throw Rikou aside while giving her a Powered Suit to act as support for the frail body. Meanwhile, Shiage finally decides to face on Mugino directly now with Rikou away from the battle.

Accelerator attacks Aiwass, but to the shock of both of them, "wings" from Aiwass proceed to attack Accelerator, enough to leave a large gash across his body. Aiwass blames Aleister for having such wings, describing it as an "anti-suicide mechanism", and urges the Level 5 to deal with them if he wishes to kill him. In response, black wings emerge from Accelerator's back, but Aiwass quickly overcomes his wings, leaving him in a state where he is forced to keep his blood flowing by using his ability. With Accelerator unable to fight, Aiwass disintegrates, and soon discovers that Accelerator disabled his connection with the Misaka Network in order to weaken the virus that was installed in Last Order which allowed Aiwass to maintain his appearance. Seemingly accepting Accelerator's actions, Aiwass allows the crystal in its head to be shot by Accelerator. The Level 5 collapses right after.

Mugino continues her attacks against Shiage. However, Shiage manages to elude her Meltdowner beams by using makeshift methods, including a pipe bomb that he used to startle Mugino with. Mugino's impulse drove her to fire a beam towards the vehicle where the pipe bomb is attached, and an explosion ripped across the passageway. Still, Mugino survived the blast and the frantic pursuit between her and Shiage continues to a fighter test facility. Without a way out, Shiage faces the full brunt of Mugino's might (even without using her ability), but he eventually uses the large fans used for air friction endurance in the facility to momentarily disable her. Shortly, he reunites with Rikou and receives a call from Saiai, telling the two to escape before an Academy City force comes to capture them. However, without having an idea of a viable hideout for the meantime, Shiage gambles on hijacking a nearby supersonic plane and barely escapes with Rikou, with an unexpected boost from Mugino herself.

Still a bloody mess after trying to attack Aiwass, Accelerator finds out that Aiwass remained standing even after seemingly destroying the core that keeps Aiwass' material form. Moreover, a halo emerges from the mysterious being's head, followed by an explosion that blows away the Level 5.

Characters
By order of appearance
 * Aiwass
 * Accelerator
 * Hamazura Shiage
 * Mugino Shizuri
 * Takitsubo Rikou
 * Kinuhata Saiai (voice-only)

Abilities

 * Meltdowner - Mugino Shizuri
 * Black Wings - Accelerator

Locations

 * Academy City

New Locations

 * Academy City
 * School District 23
 * Aircraft testing facility