Comet incident

The Comet is an incident that occured when a Comet called 'Tiamat' (From Your Name) crash landed on Itomori. Upon having the comet to hit the land, it creates a powerful shockwave that spread through almost the entire wards of Japan, which transforms humans into Conduits.

Overview
Subsequent to the comet incident, the shockwave spreads throughout the mainland which affected many people transforming them into Conduits. 78% of the people are affected by its shockwave and they are mostly children. The comet carries an invisible particle which can enters one's DNA genes and start evolving inside it, spreading through the rest of the body. This enables the user to manipulate or weaponize matter or nature without experiencing any side effects.

Trivia

 * This comet is linked to the comet in the movie Your Name.
 * The comet incident is an inspiration to the blast of the Ray Sphere that occured in the Historic District of Empire City from the video game inFAMOUS.