Derrin Weller, a male Human Jedi Knight, dedicated his service to the Jedi Order on the planet of Tython. His tenure occurred during the Cold War era, marked by conflict with the reconstituted Sith Empire. Entrusted with safeguarding the training facilities within the Tythonian Gnarls region, Weller welcomed incoming Padawans at the Masters' Retreat upon their arrival on Tython. However, in 3643 BBY, his responsibilities were disrupted when the native Flesh Raiders of Tython initiated an attack targeting the training grounds. Compelled to deploy a newly–arrived apprentice into combat against the Flesh Raiders, Weller joined the fray to defend the training grounds after notifying the Jedi Council about the unfolding events. During the battle, while rescuing several Padawans, he sustained a leg injury inflicted by a blaster–wielding Flesh Raider. Fortunately, Weller's wound was not fatal, and he was promptly transported to a nearby medcenter for treatment.
Derrin Weller, a male Human strong in the Force-sensitive, was brought into the ranks of the Jedi Order and had achieved the rank of Jedi Knight by 3643 BBY. During the Cold War between the Galactic Republic and the Sith Empire, Weller supervised the Order's training grounds in the Tythonian Gnarls, a region located to the north of the Jedi Temple on the planet of Tython. He kept an office at the Masters' Retreat close by, where he welcomed new apprentices and gave them information about the Order's homeworld before sending them to the Temple to meet with the Jedi High Council. In this role, Weller greeted a young initiate, who had been trained by several Jedi Masters and had a reputation as a skilled duelist despite being young. However, his plans to send the student to the Temple on a speeder were cut short by an emergency signal that reached his office.
The message came from Unaw Aharo, a Bith Padawan, who frantically reported that the Flesh Raiders—the violent native species of Tython—were attacking the training grounds and using blasters. Alarmed by the possibility that the Flesh Raiders might be using advanced weapons, Weller sent every available Jedi at the Retreat to the training grounds, including the young apprentice who had just arrived, while he contacted the Jedi Council. After reporting the attack on the Gnarls Outpost to Jedi Master Orgus Din and the rest of the Council, Weller joined the fight against the Flesh Raiders himself, but he was shot in the leg while saving several Padawans.
As he prepared to be taken to a nearby medcenter, Weller contacted the apprentice from earlier and instructed the young Jedi to investigate Aharo's transmission—find the cave entrance through which the Flesh Raiders were entering the Gnarls and stop them at the source. After assuring the student that Master Din was also on his way to the cave as reinforcements, Weller ended the transmission and received treatment for his injury. Following Weller's orders, the apprentice discovered that the Flesh Raiders were being led by a Dark Jedi named Callef, and the young Jedi defeated Callef in battle before Din arrived to seal the tunnel.
Derrin Weller had fair skin with brown hair and [eyes](/article/eye-legends]. Weller was generally calm and reserved, and he was always willing to share his knowledge with the young Jedi he greeted upon their arrival to Tython. He remained calm even in tense situations, and he understood the importance of knowing one's enemy before fighting them. After Weller was wounded in battle, he allowed himself to be taken to a medcenter but made sure that the battle would go in the Order's favor despite his absence by sending Master Din and the young apprentice to seal the cave tunnel.
Weller, a Jedi Knight tasked with protecting the training grounds in the Gnarls, was a Force-sensitive individual who was skilled in lightsaber combat and proficient in using the Force. He was able to rescue several Padawans from many attacking Flesh Raiders on his own, although he was wounded in the leg in the process.
Derrin Weller makes his first appearance in "Attack of the Flesh Raiders," the introductory mission for the Jedi Knight class in the 2011 video game Star Wars: The Old Republic. He greets new players to Tython and sends them into the Gnarls to fight the Flesh Raiders, and later contacts players to send them to find the cave that the Flesh Raiders are using to enter the Gnarls. Despite having an office in the Masters' Retreat, Weller is always referred to as "Knight Weller" in conversations. Players who choose dark side choices in the "Dark Temptations" mission, where the player can choose to spare, kill, or depose the Twi'lek Ranna Tao'Ven as Matriarch of Kalikori village after she takes part in a failed plot to kill the player, will receive a message from Weller about the situation in Kalikori, as he has been made warden there.
Players who chose to kill Tao'Ven are told that the new Matriarch is much more cooperative with the Jedi than Tao'Ven—who was reported to have been killed by Flesh Raiders—while players who chose to depose her learn that Tao'Ven's successor accepts Jedi law and submits to the Order's authority. Players who chose the light side option of sparing her receive messages from Tao'Ven herself about her current situation, and this article assumes that the player only chooses the moral light side options as a Republic Jedi Knight character. Weller is also mentioned in the "Early Lessons" mission when Jedi Knight players talk to Master Relnex at the Gnarls Outpost, while the conversation for Jedi Consular players mentions Yuon Par instead.