Intersection

The Intersection is an apocalyptic event in Xenoblade Chronicles 3. It is a universe-wide annihilation event that will destroy the worlds of Xenoblade Chronicles and Xenoblade Chronicles 2 collide and destroy each other.

Prelude
In the distant past, the two universes that comprises Aionios were one. In the year 20XX, Klaus activates the Conduit during an attack on the First Low Orbit Station by the Savorite Rebels in a last ditch effort to escape from the war, splitting the one world into the worlds of Bionis and Mechonis and the world of Alrest respectively, as well as flinging each half of his body to each world.

Xenoblade Chronicles 3
Years after Klaus's death in each of the universes, the worlds begin to draw towards each other, but will destroy each other if they collide. By communicating with each other, via light, both worlds made contact for the first time. The queens of each world, Melia, and Nia each constructed each half of Origin as an arc to reboot the lives of each world once Intersection begins.

When the worlds fused into Aionios however, the reboot process failed due to Z and Moebius interfering and capturing Melia to gain access to Origin and take it over, trapping the world in an endless cycle of life and death to keep the worlds frozen in time.