Convergence

The madness grows thin

Years, ages, millennia, eons have passed before the realms had periodically returned to their natural state. Is the new normal considered natural?
The confluence of the realms, meeting as giddy family members. For a brief time, realms may interact with each other, albeit for peace or conflict.
Mythos tells stories of the primordials deferring Madness, churning it away from the realms to attempting to rejoin them. Gone, or weakened, such a task is no easy feat and may not be sustainable.

Manifestation

Powerful booming, alien fauna and flora appearing, presence of a foreign body in the sky.

Type

Metaphysical, Astral