Ioulaum

Ioulaum was a great archwizard of Netheril, a beloved champion of his people and the inventor of both the mythallar and the flying enclaves of his empire. When Ioulaum abandoned Netheril to escape the “life drain” dweomers of the phaerimm in -339 DR, panic spread at the news of his disappearance, leading to Karsus casting his spell “Karsus’s Avatar.” Since the fall of Netheril, Ioulaum has survived as an elder brain (the central brain of an illithid community) lich.

Ioulaum is believed to have been responsible for the creation of the first alhoon from his illithid students (he used an arcane ritual to fuse the brains of those students into a elder brain that he then took full control of, destroying their individual wills in the process).

The Exursion Into Extinction
In -3145 DR Ioulaum led a major battle known as "The Excursion Into Extinction", bringing thousands of Netherese spellcasters and warriors to mount an attack against the largest concentration of orcs in Netheril's land at the time.

The Mythallar
Ioulaum is most famous for his invention of the mythallar  in -3014 DR. The mythallar dug deep into the raw, unfiltered magic of the weave. The arcanists of Netheril used it to create quasi-magical items - items that were permanent as long as they were within the one mile range of a mythallar.

As the Oracle of Ellyn’taal
Since the fall of Netheril, Ioulaum has survived as an elder brain (the central brain of an illithid community) lich.

Ioulaum is believed to have been responsible for the creation of the first alhoon from his illithid students (he used an arcane ritual to fuse the brains of those students into a elder brain that he than took full control of, destroying their individual wills in the process). . Today he offers knowledge Netheril's magic, for a terrible price - a  voluntary losing portions of the applicants’ sanity or pieces of the applicants’ arcane knowledge.