Teall is a planet that exists in in another dimension. Teall is believed to be a microdimension accessible only through a black hole. Like the dimension itself, the inhabitants of this realm are composed of pure energy.
Teallians can inhabit and animate nearly any matter, however the inhabited object quickly breaks down and disintegrates. The sentients there are actually remote forms of a group mind. The energy beings created a solid spacecraft, the Trans-D-Vessel, which would enable one of their number to search for other energy creatures who could be converted to the Teallian group mind.
The being who would later be known as the Legionnaire named Quislet, a singular entity with an atypical degree of independent thinking, was chosen to be the ship's pilot. Quislet, however, enjoyed his free existence and had no desire to merge with the central mind. He took the craft straight into a black hole, eventually emerging in the Earth dimension.
The Teallians tracked down Quislet's location and attempted to retrieve the Trans-D-Vessel craft and punish the traitor. Wildfire helps Quislet escapee the wrath of his people. Quislet was forever exiled from the place of his birth.