In advance of the Nagai invasion of the neighboring "Skyriver" galaxy, scouts Kor Essen and his brother Vor were sent to infiltrate the galaxy's world of gambling and organized crime. Enamored by the lifestyle they adopted, the brothers abandoned their mission.
Eventually, Kor and Vor Essen were captured by Chevin slaver Phylus Mon around 20 BBY and imprisoned in Mon's slave zoo on board the Animiasma. They were eager to escape.
The Essens, should they find any would-be rescuers, would try to bribe them with self-made Tehk'la blades or electromesh armor, because they believed that every sentient would be motivated by material goods instead of abstract morals.
Phylus Mon surgically inserted an explosive near the heart of each of his slaves. The explosive would be activated in the case of Phylus Mon's death, but it could also be deactivated with the impact of an ion weapon. All the slaves in Phylus Mon's zoo were also regularly battered.
The abuse they suffered under Mon led the brothers to reconsider their place in the galaxy's society. Escaping with fellow captives shortly before the outbreak of the Clone Wars, Kor and Vor returned to their mission and continued gathering intelligence for the planned attack.