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 " . < ref name = " N : EoM / WoN - p11 - 12 " > < / ref > Since the fall of Netheril , Ioulaum has survived as an elder brain ( the central brain of an illithid community ) lich . Activities . Under the guise of the Oracle of Ellyn ' taal , Ioulaum extracted a terrible price for the information he provided - the voluntary , permanent loss of some portion of the questioner ' s sanity or the knowledge of a powerful spell that Ioulaum did not yet know . History . Early life and The Excursion Into Extinction . Born in Seventon in - 3315 DR , Ioulaum soon rose to prominence when in - 3145 DR he 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 . < ref name = " N : EoM / WoN - p6 " > < / ref > The Mythallar Era . Ioulaum was most famous for his invention of the mythallar in - 3014 DR . The mythallar dug deep into the raw , unfiltered magic of the weave . The arcanist s 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 . With the establishment of the mythallar , Ioulaum created the first mythallar - powered item in - 3011 DR and the first floating city in - 2954 DR . The Rise and Fall of Netheril . Between - 2758 DR and - 2208 DR , Ioulaum trained thousands of arcanist s to become archwizard ' s in their own right . He also managed to greatly augment and strengthen his " mythallar " using precious metals . < ref name = " N : EoM / WoN - p77 " > < / ref > At the height of the empire ' s growth between 2207 DR and - 1206 , Ioulaum frequently journeyed across Netheril helping to establish new floating enclaves or investigating strange magic . < ref name = " N : EoM / WoN - p77 - 78 " > < / ref > However from - 696 DR the stability of Netheril became steadily undermined by both the Phaerimm and numerous disasters . This caused Ioulaum to become increasingly reclusive as he attempted to research ways of countering the threat of the Phaerimm , to the extent that he handed the day - to - day running of Xinlenal to a number of archwizards . < ref name = " N : EoM / WoN - p78 " > < / ref > As the Oracle of Ellyn ' taal . Since the waning years of Netheril , Ioulaum survived as a Lich after undergoing the transformation in - 371 DR and created a lair in the Northdark . By - 339 DR , Ioulaum fully retreated to his Northdark lair and began training an ever - growing number of apprentices fleeing the decline and eventual fall of Netheril . It was believed that during this period that Ioulaum was responsible for the creation of the first alhoon from his illithid students . In 329 DR , Ioulaum was apparently slain by a cabal of illithilich es . Ioulaum ' s last human apprentice , Tabra , witnessed what she believed to be her master ' s battle with his own students . This was actually a rite concocted by Ioulaum in an attempt to create an undead elder brain that he would then merge his own sentience upon . In revenge for her master ' s apparent death , Tabra slaughtered the last few of Ellyn ' taal ' s mind flayers by casting " Ioulaum ' s longevity " on herself in the midst of the community . She then destroyed all records of the spell ( except her own and those that Ioulaum himself had secretly hidden away ) and fled to the surface . By 1372 DR , Ioulaum survived in the form of an undead elder brain , known as the Oracle of Ellyn ' taal . Only Ioulaum ' s undead servitors and the ghosts of the mind flayers slain by Tabra remained with him . The few brave explorers who had stumbled upon the Oracle of Ellyn ' taal had gained bits of arcane knowledge dating back to the height of Netheril from their meetings with it .