Pixar's hit film, The Incredibles, utilizes Syndrome, a dangerous genius whose hatred for superheroes and superpowers stems from his own angry childhood experiences with them, as its primary villain. But while the majority of that hate is directed towards Mr. Incredible after an incident that left Syndrome greatly embarrassed, there might have been another Super with even more of an influence on him.
In the backstory for The Incredibles, the previous generation of superheroes was littered with powerhouses. Although the line of work was dangerous, there were numerous heroes, each with their own unique abilities and powers. Among them was the brilliant Physcwave, who was capable of generating mental waves that gave her control over the thoughts of others and was one of the most intelligent of the supes. Also capable of other forms of psionic abilities, she was also a member of the team known as the Phantasmics, which was focused on international threats and utilized a secret headquarters in the "mid-ocean" known as New Atlantis.
Despite her impressive powers, Psycwave was ranked with a relatively low threat rating by Syndrome's Operation Kronos, but she was still pitted against the Omnidroid v.X1 during its training stages and was reported as killed in action by the machine. In the grand scheme of things, Psycwave plays a very minor role in the story of The Incredibles. But there's a chance her true identity carried far more importance. A fan theory from Reddit user u/Spoodern suggests that she might have actually been Syndrome's mother. The theory notes that her intellect could have easily carried down to any potential children she had in her civilian identity as a psychologist, explaining Syndrome's incredible genius-level intelligence.
The theory also notes that, when Mr. Incredible caught the young Syndrome and ordered him to return to his parents, he spoke with a certain amount of force when referencing Buddy's mother, almost as if he knew her. If Buddy was the son of a fellow hero, it's likely that Mr. Incredible would be aware of him, explaining why Bob Parr put up with so many fan letters and photographs with his "biggest fan." A random fan would have likely been pushed away harsher from the get-go, but because it was the child of a superhero ally, Buddy's obsession with Mr. Incredible was given more room to grow. Syndrome's oceanic base could have also been New Atlantis, explaining who he procured the island from and why one of Psycwave's old teammates, Gazerbeam, would know a place to hide within the island and leave a warning for others. As a former member of the Phantasmics, he could have been to the island before and would know where to hide.
It's an interesting theory and one that adds additional layers of tragedy to Syndrome. The son of a Super with no powers of his own, Buddy's internal fears and hate with Supers might have partly stemmed from her. Despite this, Psycwave was given a low danger rating, potentially even as a means of making her not a target for the Omnidroid. But if this theory is correct, then Syndrome eventually turned the robot against even his own mother. The theory paints Syndrome's actions in an even grimmer light, suggesting that on top of all of his other crimes, the villain also commuted matricide on his path to becoming the greatest "superhero" in the world.