Born after the end of the Clone Wars, Naaro Viin was raised from birth by two Iktotchi prophetesses. When he was two, Viin started showing signs of prowess in the Force, which worried his mothers. As the Galactic Empire had recently been instated and had wiped out the Jedi Order, they feared they would send one of their Inquisitors to kidnap or kill their child. As such, when an Inquisitor did arrive to take Viin, the two prophetesses attempted to flee Iktotch, only for their ship to be taken in by a Star Destroyer by tractor beam. After apprehending them, Viin's parents were slain and he was taken in by the Empire to be trained as an Inquisitor.
Viin was trained in the ways of the Force by Inquisitor Zale Ven, alongside the Cerean Tarr-Nar-Mal. Viin's skills as a telepath were strongly valued by the Empire, who used them to track down other children of the Force across the galaxy. When Emperor Palpatine was killed at Endor, the Inqusitorius fell into infighting, which neither Viin nor Mal wished to take any part in. As such, they both became bounty hunters, primarily hunting down Jedi which they both excelled at.
While Mal ended up joining the Snatchers, Viin did not; he detested the then-current Boss Rex Dan'wal for evading him several times during his time as an Inquisitor. Six years later, Dan'wal was dead and Cad Bane was Boss, thus making Viin easier to recruit.
Viin remained in the Snatchers for the next fourteen years. During a skirmish on Mandalore, his old partner Mal was killed, leading Viin to resign. He instead found work with the Sith, who made great use of his abilities to hunt and kill Jedi. When the Sith were defeated, Viin found himself out of job and on the run. While trying to evade capture, he ended up crash-landing on the barren world of Kursid, where he was found by a primitive cult that worshiped the Sith.
Over time, Viin was able to acquire control over this cult. His time with the Sith had awoken beliefs he never knew he had and he devoted the cult to worshiping the Sith god Valtheran. Distinguishing themselves with red and black tattoos, Viin's cult became known as the Marked Ones.