The rival.
Especially the douchebag Machiavellian type rivals that the main character ends up friends or teaming up with after the main character 'proves their worth' to them by being stronger. No character growth outside of now they work with the protagonist.
I really want this trope to be subverted one day, like the douchey rival shows up and everyone is just like "Wow what a dickhead" and just relentlessly bullies him until he goes away.
Pretty sure you're just talking about like 12 shonen manga/anime that do this.
Jrpgs do it too.
[spoilers for Persona 5] Persona 5 had Goro Akechi. Dude is a murderous psychopath that almost succeeds in killing the main character but at the end everyone gives him a 'but you can change! Come be our friend!' speech. And then in Royal, he comes back as a comrade for the final dungeon.