Infamous Chevin slaver Phylus Mon frequently selected Force-sensitive slaves among the files of the Chevs and "freed" them to his service: He paid them a salary and said they were free - but if they tried to leave Phylus Mon's employment, they would die. Drik was one of those Chev slaves, used in Phylus Mon's security guard: The Chev was to use his Force powers to increase the battle prowess of the other guards, or to create illusions of huge predators to scare Phylus Mon's enemies, although Drik himself would not involve in any physical combat.
In 20 BBY, Drik was one of the three Chevs in Phylus Mon's throne guard, along with Niv and Tosh - all of whom hated Phylus Mon. But, like all of Phylus Mon's slaves, they had an injerted explosive that would kill them instantly should Phylus Mon die. The Chevs were sitting at their master's feet, where they could Force-affect all of the bodyguards (including a group of Coruscani ogres, and a hidden Wampa), and in a room big enough for an illusory rancor to attack.
With Phylus Mon's mobile headquarters was in the Cularin system, the throne room was attacked by a local group who opposed to Phylus Mon's plans. Phylus Mon made a threat to the group, but the sentence was really a code for the Chevs to know they should begin to Force-boost the guards.