My worst Mary Sues. Let me show you them. Describe your worst, most headdesk-worthy creation and why you like to pretend they never existed. Extra credit goes to whoever provides links to the fics in which they appeared.
Meet Alan Ketchum, son of Ash (who has for some reason become a professor). He gets a Charmander as a starter and goes out, immediately happening upon RAINTEICUNE! You see, Raikou, Entei and Suicune were running around Johto when they all of a sudden CRASHED TOGETHER with so much force they all DIED. But then they came back to life thanks to an electric spark from Raikou, combined into one! (They weren't the real Raikou, Entei and Suicune, though. They were just clones. You know, there have been a billion trainers with cloned Master Balls around cloning Pokémon using that neat PC trick.)
So, spoiled brat that he is, Alan happens to have gotten a Master Ball from his father, so he just throws it right at the thing. And takes it home. And they do a little bit of research on it, go "ooh, cool, it has three types" for a while, and then Alan gets to keep it. Because it already loved him
just that much.
Then he goes around and beats a whole bunch of trainers with it until MOLZAPART (you see, Articuno, Zapdos, Moltres and Mew were all playing in Seafoam Islands when suddenly they saw a MIST STONE and thought it was a Geodude, so they attacked it, and it CAME TO LIFE AS A COMBINED VERSION OF THEM except it didn't look like Mew at all but still had psychic powers) suddenly appeared before him and told him that Rainteicune should be wild. Meanwhile, his Charmander had accidentally evolved even though he didn't want to, and his personality had completely changed, so Molzapart decided to devolve him as repayment for releasing Rainteicune. Except that it didn't work properly, so instead Alan's Charmander got the power to EVOLVE AND DEVOLVE AT WILL. But he still got his old personality back so everybody was happy. Except his Charmeleon personality which died forever.
And the funny thing is that he wasn't even a Gary-Stu. Honestly. The description makes him sound like it, and any Mary-Sue test would mark him as over-the-top Sueish, but the thing is that I didn't care one bit about him. He was just a random plot device I put in to explain how Rainteicune was discovered, because as far as I was concerned I was writing a story about my awesome fake legendaries Molzapart and Rainteicune. The stuff about his Charmander evolving was something midway between an author tract about how Pokémon evolution is eeeevil (I have no idea how I came to that conclusion, because I always evolved all my Pokémon on my games) and an excuse to make him use exclusively Rainteicune for all his future battling. And then I had to fix that somehow because I couldn't just make his Charmander lose his original personality forever and Charizard was my favorite Pokémon, so hey! Make him gain the ability to evolve and devolve at will! Meanwhile, Alan was just kind of there. The real Sues in that fic were Molzapart and Rainteicune, really, except for the part where they weren't actually characters, really. It's quite an odd story.
Molzapart and Rainteicune!