Annihilation event

Annihilation events are a phenomenon Xenoblade Chronicles 3. They are destructive events that damages the landscape of Aionios.

Description
Annihilation events are not well understood by the people of Aionios. They are treated as a natural event that can occur without warning in any place at any time, generally caused by a buildup of black fog in the area. This is later used to create the Annihilator, a device that weaponizes black fog to trigger annihilation events at a distance.

While black fog is the predictor and cause of an annihilation event, there is no advance warning when one finally happens. A flash of light envelops a spherical area for a short time, followed by everything in said area vanishing without a trace. Anything on the edge of the effect is cleanly cut; anything above it may end up floating in midair instead of falling into the vacated space. Thus, within the space of a few seconds, a perfectly round hole appears in the landscape.

Story
The first annihilation event seen is in the opening sequence where one destroys a middle section of the Urayan Mountains, followed by other smaller annihilation events in the surrounding areas.

Annihilation events occur frequently Eagus Wilderness. When the party goes swimming at Lake Rezzento, a suspiciously round body of water, Taion warns Noah that annihilation events occur often in the wilderness.