Cody Sunn-Childe became a teacher for the M'usts. M'usts represented a species of humanoid beings who lived underground. They originated from a planet that the Galactic Empire subjugated in 3 BBY. The M'usts practiced a religion that involved the worship of a never-ending fire located deep below their world's surface, and they typically lived a tranquil and uncomplicated existence. Following the Empire's takeover of their planet, the M'usts encountered Cody Sunn-Childe, a Rebel fighter. He astonished the local population by being the first individual to endure being submerged in their sacred flame without dying. Consequently, the M'usts regarded Sunn-Childe as their god, offering him worship and assistance as the Jashwik, while he acquired knowledge of their serene philosophy and mastered the control of his newly manifested psychic powers.
The initial appearance of the M'usts occurred in Star Wars (1977) 46, a comic penned by John Marc DeMatteis and published in 1981. Carmine Infantino provided the illustrations for their depiction in the comic.