A race of aliens known as the Bern are guilty of ruining the heroic legacy of Sonic the Hedgehog more than Dr. Robotnik in the discontinued Archie Comics series. These extraterrestrials aren't even the Xorda who actually attacked the Blue Blur's planet of Mobius and thrust him into space. Ironically, the Bern are pretty much on Sonic's side, too.
Sonic's first meeting with the Bern initially seemed to work in his favor. In reality, it actually caused a devastating string of events that eventually led to the destruction of his home. After Sonic straight-up murdered Robotnik, the mad scientist was replaced with a robot before the two were abducted by aliens. During their imprisonment, the two enemies learn they must fight each other in a transformative battle that would decide their bodily composition, in issue #118 by writer Benny Lee, penciler Steven Butler, inker Jim Amash, colorist Jason Jensen and letterer Jeff Powell. At the start of the altercation, the aliens turn Blue Blur into Mecha Sonic and Robo-Robotnik into an organic lifeform. The contestants are then told that the winner will return to their normal body type while the loser will be forced to remain in their altered form. Of course, Sonic wins and reverts back to an organic hedgehog while Robo-Robotnik loses and remains an organic humanoid.
However, the consequences of this odd event are more complex than the immediate implications of Sonic's victory. They would later drastically change the course of the series while continuing a long-forgotten plotline that once prevented the upcoming ramifications from transpiring sooner. Much earlier, the original Dr. Robotnik had learned the location of Sonic's hidden base but failed to act before Sonic outright murdered him in the EndGame arc. Although dead, Robotnik's memory was stored in a supercomputer that his replacement, Robo-Robotnik, tried downloading to carry out his predecessor's plot. But Sonic and his allies had preemptively installed a virus in the same computer that Robo-Robotnik soon interfaced with, resulting in Robo-Robotnik losing all knowledge of the data he downloaded. But upon the aliens' contest in issue #118 that reverted him into an organic lifeform, the virus was no longer in effect, allowing him to remember the data, which eventually culminated in the villain destroying Sonic's home.
Aside from serving as a continuation of a much older story that eventually led to Sonic's home getting destroyed, the comics later reintroduced the same Bern aliens in a more meaningful way that sidelined Sonic. When Sonic is later thrust into space at the end of issue #125, he stumbles across the same alien who experimented on him and Robo-Robotnik, learning that the extraterrestrial was behind an even earlier mystery when all of Sonic's friends and family who had been roboticized were transformed back into organic animals - except his father. Readers understandably came to the assumption that Sonic would be the one who would restore all of his roboticized friends and family. But he wasn't. He was upstaged by a random alien. Adding insult to injury is the fact that Sonic didn't restore the freewill of these roboticized animals. His girlfriend Princess Sally did.
Although Dr. Robotnik (or Robo-Robotnik) destroyed Sonic's home, the evil mad scientist wouldn't have been able to if the aliens hadn't performed their experiment on him and the Blue Blur. These same aliens also beat Sonic to the punch of playing the ultimate role of hero by restoring Sonic's family, which he couldn't save, instead of him and everyone else who had been roboticized by the actual Dr. Robotnik. Although Sonic the Hedgehog has faced many challenges, roboticization has been the center of his struggles and even predates the events of the comic itself, robbing him of his greatest legacy.