Fixit was discovered by Relic the Pika at some point, and the archaeologist made a determined effort to discover the origins of her ancient assistant. While the world below was torn asunder, Fixit attempted (and failed) to decipher the user interface for an ancient computer database in the Launch Base Zone for his master Relic, whom he addressed as "Madam Relic." While she struggled to decode the data herself, Fixit informed his master that Guardian Knuckles the Echidna had arrived. With Knuckles entrusting the Master Emerald to Relic while he searched for the Chaos Emeralds, Fixit remained on Angel Island to support her. The two attempted to access some of Angel Island's systems, but they proved incompatible with Fixit's systems. However, he was able to detect a strange energy signature in Mushroom Hill Zone, which the pair proceeded to investigate. They came across a strange plant which they took a sample from to analyze, only to discover that the island had been invaded. (SU: #63, #64, #65, #66)
After reporting their findings to the returned Knuckles, Relic and Fixit joined him in "welcoming" some unexpected guests: Team Dark and a Tele-Pod device that allowed Dr. Julian Snively to communicate with them. Fixit and Relic remained on Shrine Isle with Shadow the Hedgehog while Knuckles took Rouge the Bat and E-123 Omega to search for the invaders, whom Team Dark revealed were remnants of the Black Arms. The leader of these creatures, Eclipse the Darkling, attacked the shrine in an attempt to claim the Master Emerald, though the resulting battle between him and Shadow resulted in his defeat. However, Shadow then determined to move the Master Emerald to a G.U.N. facility to keep it from Eclipse, and instructed his teammates to take Knuckles and his friends back to their arrival vessel. Knuckles refused to cooperate and engaged Shadow in battle, but fortunately for Fixit and Relic Rouge felt that Shadow was out of line. Unfortunately, they then suffered another attack by Eclipse, this time in the company of his Dark Arms, who subdued the agents and destroyed Snively's pod. After they departed for Team Dark's vessel with the Emerald, Fixit was tasked with repairing a damaged Omega, a task he took on reluctantly given the more destructive robot's tendency to antagonize him. He eventually aided Team Dark in slowing Eclipse down long enough for Shadow and Knuckles to catch him, and the Master Emerald was shattered as a result. Knuckles subsequently departed to find the shards before the planet below could be restored and Angel Island fall as a result, prompting Fixit to remain there with Relic to help watch over it in the Guardian's renewed absence. (SU: #67, #68, #69
Fixit is very polite and proper, often addressing others by titles of respect. He also abhors violence, being designed for repair and assistance. While usually genial, he does not enjoy being antagonized.
In terms of mobility, Fixit is notable in that he hovers above the ground rather than walking or using treads or wheels for locomotion. He is a well-equipped mechanic, as shown by his ability to repair damage done to Omega. While he has the ability to interface with other machines, it is not without limitations, as shown by his inability to properly connect with the ancient computer systems on Angel Island that Dr. Eggman had modified. Given that he is apparently intended to repair technology, he is not equipped with any known weaponry.
Fixit bears some resemblance to another mysterious ancient robot, the destroyed Emerl, in terms of his orange and yellow armor and the triangular pattern of circles on his chest. However, Fixit has a head fixture resembling a hat more than a fin, and his eyes are green orbs while Emerl's were blue ovoids. Fixit has dark orange upper arms and shoulders that are much thinner than his cone-like forearms, which are a shade of yellow except for orange rings at his elbows and wrists. He has yellowish hands that each feature two fingers and a thumb, and in place of legs he has a cone-like aperture of matching color that seems to function as a sort of engine. His chest is also more box-like than Emerl's, and he sports a large square container on his back that is dark orange marked with an alternating yellow and black strip. This container has a large curved bar on top of it, and serves to carry Fixit's various tools.
- Despite the realignment of comic continuity to better match that which was established in the games, Fixit's existence appears to contradict information given in Sonic Chronicles: The Dark Brotherhood indicating that fellow Gizoid Emerl was the only escapee of the Argus Event.
- Ian Flynn later indicated that Relic found Fixit on Angel Island. 
- Fixit appears to be very unusual compared to other Gizords. Other than his unique design, it doesn't seem that he was built for destruction, but rather for construction. Niether does he appear to be interested in power, nor forming any new "Links" with others who display that power.
- Sonic Universe #68's Off-Panel featured Fixit parodying the Wreck-It Ralph character Fix-It Felix by uttering his catchphrase "I can fix it!" However, Fixit found himself forced to contend with the immense destructive potential of E-123 Omega.