After months of war between the Autobots and the Decepticons on Nebulos, the Nebulans no longer cared who won, as long as the fighting stopped. When Fortress Maximus and Scorponok forces left for Earth, the Nebulans took advantage of the opportunity to poison all of their fuel and energy sources, rendering it unusable by any Transformer.
The scientist who had devised the toxin, Hi-Q, soon had a falling out with his partner Hi-Test. When a pair of Decepticons named Darkwing and Dreadwind arrived and were immobilized by the tainted fuel, Hi-Test saw an opportunity. Undergoing a binary bonding process with the Decepticons, Hi-Test changed himself and his ally Throttle into the first Powermasters. Using this new process, the Decepticons were able to function on the poisoned planet of Nebulos by using their Powermaster partners as living batteries.
A small team of Autobots soon arrived on Nebulos, hoping to construct a new body for their leader, Optimus Prime. Seeing the Decepticons running rampant, they tried to stop them, but soon began to run low on fuel. Hi-Q used the same binary bonding process as Hi-Test, bonding himself to the body of Optimus Prime. His fellow scientists also bonded themselves to the fallen Autobots. The revitalized Autobots quickly defeated the two Decepticons.
An ancient Cybertronian known as Overlord was responsible for the creation of the Powermaster process. It was designed as a way for them to survive on any world. By capturing hostile natives and reformatting them as biological power sources, they could greatly reduce their dependency on energon. The process was perfected on Nebulos. Organics who undergo the binary-bonding process are indistinguishable from their fellows when not wearing Powermaster armor, though they have enhanced strength, endurance and mental abilities.
The Powermasters were created by Hasbro and Marvel for the Headmasters (1987) series and Toyline. They were first seen in The Transformers: Headmasters #4 by writer Bob Budiansky and editor Don Daley.
Powers & Weaknesses
Like the other binary bonding technologies, the Powermaster procedure requires cybernetic surgery and specially designed power armor. These changes allow an organic being to transform into a powerful engine and bond themselves to a modified Transformer. The initial advantage to this procedure was survival of the Transformers who were unable to use the toxic fuel sources of Nebulos, the Powermasters provided an alternate source of energy.
When non-toxic fuel sources are available, Powermasters function as a power booster or turbo accelerator, giving the Transformer a surge of additional power for increased strength or speed.
While serving as an alternate power source the Powermaster partners had extremely high metabolisms, meaning that they need to eat large quantities of food at regular intervals just to keep themselves from starving to death. A Transformer who has undergone the Powermaster conversion can't transform from alternate mode into robot mode without their partner.
Over time, the bonding procedure for has the risk of both partners being absorbed into a single mind and identity. This happened to Hi-Q, who merged with Optimus Prime and after Optimus's death it was shown that his mind had merged with Hi-Q.