Athalee was in a forgotten past a scholar who lived and died in Kryptgarden.
In 1489 DR, the Red Wizard necromancer Zaralda raised him as an undead like many others. However, he was able to resist the compelling orders of the necromancer. Hating his new condition, Athalee attacked Zaralda and her allies, hoping to die with his tormentor.
In the end, after an attack in which he killed many cultist and Thayans, an adventuring party hired to defeat Claugiyliamatar assaulted Zaralda and her minions. Sensing the good will of the adventurers, he tested them to solve a riddle. After they solved it, Athalee manifested and offered his aid against Old Gnawbones in exchange for the death of Zaralda and the adventurers agreed.