- Real name: Originally, none; later Brains
- Occupation: Mobile Robot Factory
- Known Relatives: Inapplicable
- Group Affiliation: The Council
- Base of Operations: Chicago, Illinois
- Height: 10'6"
- Weight: 4,750 lbs.
- Eyes: Photocellular
- Hair: None
Matrix-Prime is a sophisticated robot created by scientists working for the Council in its original headquarters at the bottom of Lake Michigan. Constructed from an ultra-tough metal and fitted with vocal equipment, the huge robot is originally made for flying only, having rocket tubes instead of legs. It is first sent to steal for the Council, keeping off antagonists by creating smaller robots of various types to do battle, then return within it to be recycled for the next robot productions.
During her first encounter with the machine, Supergirl is astonished when her first blow fails to destroy Matrix-Prime. She is even more amazed when the metal goliath sends deadly robots to battle and delay her while it makes its escape. This, however, is where the monster's creators miscalculated, as the Girl of Steel is able to finish off the last robot and rockets in time to trail Matrix-Prime to the underwater headquarters of the Council.
It is there that Brains, leader of the Gang, uses a device to take over mental control of Matrix-Prime for a battle with Supergirl. When the Maid of Might defeats the robot, Brains lapses into a coma and Supergirl arrests her. The leaders of the Council, however, evade capture.
What Supergirl did not realize is that in beating Matrix-Prime while it was being mentally dominated by Brains, she causes a feedback that fuses the consciousnesses of the robot and the woman, so that Brains is later able to summon the rebuilt Matrix-Prime to break her out of jail. This time, Supergirl is suffering from a strange form of radiation sickness, and she is captured and turned over to Lake Shore University's Professor Drake, a Council scientist, for an experiment that goes wrong. When Supergirl later finds him, Drake has been killed by a massive blow to the head that crushed his skull—presumably the work of Matrix-Prime.
Once more, Matrix-Prime faces Supergirl, this time capturing Dr. Barry Metzner and taking him to a man named Burroughs, about whom Metzner is writing a potentially damaging book. When Supergirl comes to the rescue this time, she finds that her previous encounters have given her all the practice that she needs to defeat the robot—even though it has now been improved and sports a pair of powerful legs. This time, the robot's body is damaged beyond repair—though what became of Brains herself is not known (DNAS No. 6, Apr 1983: "Battleground O'Hare"; DNAS No. 7, May 1983: "This Meeting Will Come to Disorder!"; DNAS No. 10, Aug 1983: "Radiation-Fever!"; DNAS No. 12, Oct 1983: "Guess Who's About to Die!"; SG2 No. 17, Mar 1984: "Publish...and Perish").
Powers and Abilities
Matrix-Prime was created as a huge robot of tremendous strength, with the ability to fly at great speed. It was also a robot factory, able to create in mere moments within its body, whatever types of miniature robots it needed and send them out to do any work it deemed necessary. Its mind, however, was limited, and so it was unable to function at maximum capability until Brains gained mental control over it. Among the small robots Matrix-Prime produced were armored humanoids wielding ray guns, worker-drones to do various jobs, small rockets fitted with sensors to feel out a foe's weaknesses and attack them, powerful explosive rockets, and drones able to turn Supergirl's heat vision back on her.