“You are the one that stands at the center of all this, Kamijou Touma.”

“What…?”

“I lost the arrow in that conflict. And I needed to acquire it once it appeared again. So it would be no exaggeration to say I built Academy City in order to attract the Kamijou Touma who would eventually be born.”

“…”

“Imagine Breaker’s power is only noticeable when surrounded by people with supernatural powers. Kamijou Touma will not express his tendency toward conflict if no one needing help is within arm’s reach. …And yet you were able to make your presence perfectly known. Why was that? Isn’t it obvious? Because a stage covering western Tokyo was remade into an esper development institution that followed the perfect theory that would allow Kamijou Touma his greatest performance.”

[...]

Having lived and lost his memories in this city, Kamijou had no knowledge outside of what was found in Academy City. This city was like his hometown. He had assumed the way things felt here was the same everywhere and understanding that was enough to have something in common with everyone in the world.

But what if that had been prepared for Kamijou Touma before Kamijou Touma had even been born?

[...]

If Kamijou Touma had been an intellectual boy who loved shogi, this city would have been filled with people sitting at shogi boards and moving shogi pieces.

If Kamijou Touma had been a sensory boy who loved cooking, this city would have been overrun with cooking battles that stimulated the senses with flavors, colors, smells, sounds, and aromas.

If Kamijou Touma had been an athletic boy who loved mountain climbing, this city would have been packed with climbing duels in which contestants climbed up the walls of the high-rise buildings.

But that boy had entrusted his life and lifestyle to his right fist.

Thus, Academy City had taken this form. So that it allowed his violence to bloom to its fullest.

“I was the one that prepared the board, lined up the pieces, and constructed the stage.”

Toaru Majutsu no Index New Testament vol.18 ch.3 pt.14