Mylar and the fall of Nerul

The rise of Nerul
The first Abberant Nerul's origins are unknown. Nerul led an army of Aberrations to conquer the first world and few could stand against him. His forces were split to three main branches:

The Illithid - Powerful and brilliant the Illithid were the main power behind Nerul. Advanced in spellcrafting, technology, and martial combat Nerul could well have succeeded with just this force.

The Dopplegangers - What might would not solve, subterfuge could. The Dopplegangers infiltrated society well ahead of Nerul's arrival ensuring a weak resistance.

The Abberants - Nerul's shadowy nightmare things. Anything he cooked up in the dark corners of his mind he could make real. Horror itself is a fine weapon.

Mylar
The Illithid city of Mylar was created by the inventor Kothar as Nerul began to establish a strong foothold. The city itself acts as an elder brain for the inhabitants; allowing them to live free from Nerul's direct influence and advanced far faster than the rest of Aberrant Society.

The Hydra
When The Hydra landed Kothar was quick to act; establishing a magical tether between Mylar and The Hydra they were able to halt its attack. A blast of psychic energy that would have destroyed the minds of all natural life on prime, starving the Aberrants of their food source, was instead redirected and controlled. Kothar used the energy of The Hydra to further power and, in doing so, freeing their people from the need to feed on Humanos brains.

Nerul's betrayal
When this technology was offered to Nerul and the empire he gladly accepted only to inevitably warp this power to his will. Focussing the energy of The Hydra, Nerul was able to subjugate every thinking creature to his will in an instant. Nerul and his empire's remaining conquest of the plane was swift and absolute.

The Erasure
Whatever force had sent The Hydra it had sent it with the apparent intent of stopping Nerul. As this was clearly unsuccessful their final approach was annihilation. Without warning existence itself was wiped clean. Kothar exploited the tether and the power of The Hydra to escape destruction; shifting Mylar slightly out of sync with reality, where they have remained ever since.