Zwei

Zwei was the first Netherese arcanist to be credited with the creation of new spells. He or she introduced the three successively more powerful extension spells in the years 1280 to 1300 NY of Netheril's Silver Age.

All other facts about Zwei's life (including their gender) were lost to history.

Trivia
The Zweihausen were a pair of enormous houses on Netherese territory that were destroyed during the rise of human civilization. It is not known if Zwei was related to the Zweihausen or the namesake Zweihaus River.