Xan-Yae
From Merric's Greyhawk wiki
Xan-Yae is the True Neutral Goddess of Mental and Physical Mastery of Mind over Matter, Twilight, and Stealth.
Her followers include those who seek mastery of their mind and body, as well as those who favour twilight: monks, thieves, as well as young lovers and those of cautious nature.
Her High Priest in the City of Greyhawk is Yahlos.
