Paul Norbert Ebersol was clearly a genius from a very young age. At the age of three he disassembled, repaired and reassembled an alarm clock, at ten he built an electric car and by the age of thirteen he built a robotic arm from spare parts. Since school wasn't challenging enough he dropped out and moved around quite a bit eventually turning his technical genius to committing high tech crimes. To this end he took the name Fixer for himself and began working with Marvin Flumm a former SHIELD telepath who went by the name Mentallo.
Fixer was created by Stan Lee
and Steve Ditko
and first appeared in Strange Tales #141
Mayor Story Arcs
Masters of Evil
The Fixer was part of Baron Helmut Zemo's Masters of Evil and he was instrumental in their takeover of Avengers Mansion though he was more interested in getting closer to the criminal Yellowjacket aka Rita DeMara, the other genius in the group.
When Helmut Zemo hatched his plan to replace the missing Avengers and Fantastic Four with former Masters of Evil Fixer was the man he turned to to rebrand them as new heroes. Fixer brought Erik Josten back to Earth to become Atlas, built the sonic harness for Songbird, the MACH-1 armor for the former Beetle, a morphing tech-pac for himself as Techno and all the other technology for the team. Early in their career his body was killed and his mind was transferred to his tech-pac making him more of a shapeshifting robot which he enjoyed immensely. When Baron Zemo hatched his plan to take over the world Techno was the one to remain loyal to him for quite some time, through several plans until Zemo no longer needed him and he returned to the Thunderbolts. Infiltrating the Thunderbolts new base he knocked out their new technical expert Ogre and took his place on the team.
When Scourge was ordered to kill the Thunderbolts he began with Jolt, but Techno had plans for her and recovered her body starting a process that would eventually return her to life. After Baron Zemo himself was killed Techno was the next target of the assassin and despite his seeming immortality his robotic body was overwhelmed and he perished. However he had planned for every eventuality and created a failsafe for himself and Zemo, should either of them be killed they would be placed in another living body. Ebersol awoke in his lab at Zemo's castle to find it full of SHIELD agents, they offered him a place on a team of Redeemers to take down the Thunderbolts and uncover a large scale plot. His tech-pac was now responsible for keeping his body alive and SHIELD had the control codes to the tech-pac so they could kill him at any moment. It was at this point in his career that he took the name Fixer again.
Fixer stayed with the Redeemers as they took over the Thunderbolts name and headquarters though his arrogance put the whole team in danger by trying to find Ogre and discover his secrets. The Ogre had been safeguarding a dangerous mutant who could threaten all life on Earth, and Fixer's interruptions accidentally freed Humus Sapien from his stasis. Immediately after dealing with Humus Sapien the new team had to deal with the return of Graviton which brought Songbird, MACH-3 and Moonstone back to the team. In defeating Graviton most of the team was shifted to Counter-Earth located on the far side of the sun. Baron Zemo who had been controlling the Redeemers leader Citizen V was somehow downloaded into the Fixer's tech-pac during the battle and now he ordered Fixer to find a new body for himself or he'd sever Fixer's nervous system. Fixer downloaded Zemo into his Counter-Earth counterpart and they reunited with the Thunderbolts to save Counter-Earth and become heroes. When the Thunderbolts managed to return to their Earth Fixer helped restore Atlas' growth powers and left the team yet again.
Thunderbolts under Luke Cage
He has since been working with the Commission of Superhuman Activities during the Civil War and Secret Invasion. When Luke Cage took over the leadership of the Thunderbolts from Norman Osborn, he was one of the members of the original Thunderbolt's assisting him with the latest incarnation of the team, along with Mach V and Songbird. With the resurfacing of Baron Zemo, Fixer has shown that he has not completely left villainy behind. He helped Zemo with his plot against Bucky Barnes and caused an explosion that landed Falcon in the hospital. However, he is still working with Cage's Thunderbolts and covered up his absence by claiming he was ill.