In his youth, Quaervaxthanus was blinded by an older eye tyrant that was trying to eliminate the beholder bloodline of which Quaervaxthanus was member. He managed to escape despite the mutilation and disappeared for a long time.
He came back many years later as a powerful beholder mage with many powerful Netherese wands and scepters grafted into his empty eye-socket and controlled with his mind, thanks to many new spells. Quaervaxthanus was so known for his talent in spell alterations that some reclusive human archmages traded with him.
After becoming Magister, Quaervaxthanus freely visited some elven mages and gave them new spells instead of killing them like he did all wizards who sought him out.
His doom arrived in 705 DR when the human sorcerer Almer Garanthund lured Quaervaxthanus into a sophisticated trap inside a tunnel full of explosive wands. The beholder magister died in the explosion.