Bastian Thermandar was the second-in-command of the Cult of the Eternal Flame at the Temple of the Eternal Flame in Tyar-Besil in the late 1490s DR.
Bastian was a very paranoid individual, not trusting anyone. He was also greatly ambitious, scheming to gain for himself Tinderstrike and supplant Vanifer.
Bastian learned much of his elemental magic from Vanifer herself. In 1491 DR, Bastian was responsible for guarding the northern half of the temple.