C5-M3, also referred to as Healer, was a medical droid who became part of the Directive 7 group. This group was led by Mentor during the Galactic War, a conflict between the Galactic Republic and the reborn Sith Empire. While C5-M3, who became known as Healer, was a believer in the movement's principles, he ultimately turned against Mentor when Mentor integrated the majority of the droids into his own mind. Consequently, C5-M3 sought assistance from the galactic forces, aiding them in penetrating the movement's stronghold on the moon Zadd and eliminating Mentor.
In the Flashpoint "Directive 7" within the video game Star Wars: The Old Republic, C5-M3 is a prominent character.