The Vein of Dissolution! I
Countless lineages were absorbed into the folds of the Vaults of Extremity and spread out across different factions over the eons that passed.
If they held grand destinies and Providence, they may just be capable of speedily expanding their Boundaries towards Extremity- or even be capable enough to become Apex Aeonic Lifeforms.
Genesis and the Ancestors of the Barren Lands were merely lucky enough to find access into the Havens of Extremity first even before the Initiation Step of the Extremity Vein began in the Haven they were in.
It was a great opportunity as many of them rose in power, but they couldn't Conquer or advance as much as they wished to due to other Lineages that already had their Planes of Existence here- Lineages like the Noblesse!
Thus, they sought for greater forms of power.
They abandoned their Plane of Existence entirely and even used Minor Planes to bind the Major Plane.