Garen Muln studied at the Jedi Temple on Coruscant during the time that the legendary Obi-Wan Kenobi studied there. The two became quick friends, and it was often said that the two resembled one another. Because of this, Garen was used as Obi-Wan's double when the Jedi were attempting to ambush the Dark Jedi Xanatos as he attempted to steal a collection of vertex crystals. Later on in his career as a Jedi, Garen studied to be a pilot and starfighter at the training facility on Centax 2, run by Jedi Knight Clee Rhara.
However, sabotage at the facility only strengthened the Senate's fears of such a facility, whose program was cancelled shortly after. However, Garen's piloting career did not stop with the closure of the training camp on Centax 2. Clee Rhara took Garen Muln on as her Padawan, and the two explored the galaxy, distinguishing themselves among the Jedi. About a decade later, Garen assisted his old friend, Obi-Wan and his Padawan, Anakin Skywalker, as something from Obi-Wan's past caught up to him.
The whole fiasco with the Dark Jedi Xanatos, which also resulted in the death of student Bruck Chun, came back in the form of Bruck's family, who blamed Obi-Wan for his death. Garen assisted Obi-Wan and his apprentice unravel the mystery of who was trying to kill them. After this plot was finally dealt with, Garen continued his service to the Jedi Knights, as, not surprisingly, an excellent starfighter pilot.