The Sundering

About two hundred years ago, the bonds holding the world together came apart. In the wider Honkai series this kind of catastrophe is simply called the Honkai; in Nexus Anima it's the Sundering.

Before it, the Nexus linked all things. Above all, it held each pair of opposing Aspects (Love and Hate, Light and Dark, Life and Death) in balance. The Sundering tore that web apart. The severed bond-fragments took on life as the creatures we now call Nexus Anima, and the single world shattered into 81 Planes, each drifting on its own.

The old rulers who survived, the Sovereigns, became the Novarchs of this broken new world. Much of the cast's backstory traces back to this moment, and to the figure blamed for it: the World-Ender. Why it happened, and whether it can be undone, is the question the story is built around.