C5-M3, or Healer, was a medical droid that joined the Directive 7 movement headed by Mentor during the era of the Galactic War. Healer, as C5-M3 became known, believed in the ideals of the movement, but rejected Mentor when Mentor absorbed most of the droids into his own consciousness. As a result, C5-M3 reached out for help from the galactic powers, and helped their forces infiltrate the movement's base on the moon Zadd and destroy Mentor.