Ilserv originally acted as an emissary and ambassador of Ch'Chitl to the surface until, by accident, the beholder crime lord Xanathar petrified him. For many years, Ilserv was one of the statues in a rock garden near Mirt's mansion.
However, Ilserv maintained a little awareness and psychic power. Finally, in 1367 DR, Ilserv dominated the mind of a wizard guest of Mirt who reversed the transformation. Immediately, Ilserv returned to Ch'Chitl, refusing to ever go back to the surface. Thereafter, he was considered the city's sage about all surface matters, thanks to knowledge gleaned from reading minds in the garden.