Plundering Luck is bullshit. The amount of young masters smugly plundering luck from "the protagonist" is a trope that is out of control! Why can't I ever find a villain novel where the MC isn't a loner or tries to steal everything the hero has?
Slice of life Pokémon stories. I know I'm in the minority here, but damnit, every game has you curb stomp an entire fucking country with WMD's. Pokémon are ripe for crossovers or with ancient Japanese lore. For godssakes, does no one know about Pokémon Conquest?! You can literally play as Nobunaga and conquer "Kanto."
Horror stories. Can a brother get a horror story where the MC doesn't have a system that tells him every single clue to escape? Why is it that the MC is always clueless, acting clueless, or innocent? They don't need to be a sociopath, but it would be cool to see some legitimate mystery, and maybe have them learn how to fight back. I really want to read a horror story where the MC has balanced strength, can fight off the weirdness, but also knows when to run. One where he isn't a brain dead arrogant asshole psychopath, where they grow too strong too fast, or a coward...too bad horror isn't popular at all as a genre.
I hate people's lack of imagination. That they cannot fathom a crossover, or a minor crossover of three franchises+. I know bloat is a thing, and things can get complicated...but what is so difficult to understand mixing 3 related genres? If Devil May Cry, Bayonetta, and Nioh into one crossover, would it really be that difficult to grasp? They're all demons, and all Japanese shit. Imagination is lacking, and we suffer as a result as only the same old tried and true bullshit gets repeated on loop. Enjoy your Naruto SI that romances fem Naruto/Sasuke. Or your Worm fic that is kind to all the girls, acting as a rock for their mental deficiencies. Laugh at your Percy Jackson fics where Zeus is always a raging asshole, and Poseidon is chill af. Read the same slop over and over and over.