The Brainmasters are the elite members of the Galactic Defense Force Sector One troops. Oftentimes the term 'Brainmasters' was used as a team name to refer to the three members of the Car trio: Blacker, Laster, and Braver. The Brainmasters served as a counterpoint to the Decepticon/Destron Breastforce. In general, the Brainmasters were superior one on one but could be overpowered by the more numerous Breastforce.
The Brainmasters are a similar concept to the Headmasters in that a smaller robot forms the central component of the larger robots. Instead of having the pilot form the entire head, as with Headmasters, the pilot of a Brainmaster forms the face and torso interior of the larger robot. Possibly the larger robot body is a transector too, or it might be the original body with the smaller robot being an upgrade unit. What advantages this provides the Autobot is unclear, though each of the recognized Brainmasters is known as an elite level warrior but that might have been true before becoming Brainmasters.
Members of the Brainmaster sub group include:
The car Brainmasters serve in the Galactic Defense Forces Sector One Unit over seeing Earth while Star Saber served as Supreme Commander over all of the GDF from Planet V. Shortly after an attack by Deszaras on Earth, Star Saber joined the other Brainmasters there, replacing God Ginrai in command.
The Brainmasters served as the front line unit against the Decepticons while training the junior Autobots of the Multiforce and Rescue Patrol Team. For a long time they were the undisputed masters, defeating the talents of the Breastforce and laughing over the ease of defeating the Dinoforce. However, with the appearance of Liokaiser the Brainmasters were finally overmatched as the Decepticon Gestalt proved stronger than both Star Saber and the combined form of Road Caesar. However that wouldn't deter the elite warriors and all four Brainmasters strove to become stronger until they finally defeated their Decepticon foes.