Guun Han Saresh was a powerful Twi'lek Jedi Knight of the Old Republic. With green-skin and red robes, Guun Han preferred to use a Force-empowered sword over a lightsaber. Following the Sith Wars in which Exar Kun launched an attack against the Republic in an attempt to bring about a rebirth of the Sith Empire, Guun Han Saresh joined the rest of the Jedi Order in trying the heal the galaxy's wounds from the devastaion of war. During the rebuilding efforts however, some Jedi went missing. Some were never found, but some Jedi were recovered dead, bodies mutilated; obviously the work of some horrific monster.
The Jedi Council performed an investigation into the deaths and disappearances and discovered that on a number of worlds, a fiercesome beast, known as a terentatek, had emerged and preyed on the Jedi Knights. Knowing that the threat of these beasts was too great to ignore, the Jedi initiated a plan to hunt down and destroy the beasts. This became known as the Great Hunt. During the hunt, Guun Han Saresh teamed up with Jedi Knights Shaela Nur and Duron Qel-Droma. The trio found that they complemented each other very well and soon emerged as some of the greatest terentatek hunters. Toward the end of the great hunt, Guun Han found himself on Tatooine with Shaela, Duron, and Jedi Knight Cale. There, the Jedi put an end to what would officially be the last of the terentateks. Soon after, the Jedi Council declared the Great Hunt over.
Unofficially however, there still remained terentateks on one of the most feared planets in the galaxy: Korriban, a Sith homeworld. While the threat of the terentatek was great, the threat of the Dark Side was even greater. The Jedi Council had to be sure that whoever they sent would be able to resist the pull of the Dark Side which permeated the landscape and catacombs. Familiar with Guun Han, Shaela, and Duron's successes with the terentateks, the Jedi Council believed that with the bond the Jedi shared, and through supporting each other, they would be able to resist the temptation of the Dark Side.