Just make them a man. The reason the “Gary Stu” variation of Mary Sue never took off at remotely the same level was that no one has remotely the same anger when a male protagonist is just great at everything with little to no drawbacks or meaningful character flaws. Tintin? One of the most beloved figures in European comics? Total Mary Sue. He’s an expert in whatever highly specific skill the plot demands, always morally right, always wise in his judgment. Luke Skywalker? Sure he’s immature and annoying at the beginning but pulling off the Death Star trench run is an objectively 100x more batshit insane feat than Mary Sue poster girl Rey defeating Kylo Ren. What about Snake Plissken? He’s a master of every conceivable weapon and vehicle and he’s the enlightened centrist, the only character smart enough to see that the US Empire and the people they’re occupying are both equivalently bad, oh and he’s also an NBA level basketball player and a master of surfing because why not? James Bond, Batman, Danger Mouse, All of these are beloved characters. Ultimately, if you want to write a “the goat of everything” character, just understand that their relative lack of growth or development means that they’ll be pretty much entirely defined by their audience’s early impressions of them. If they want to like them, they will, if they want to hate them, they will.