I am fan of the the comics and would like to dive into another superhero run that has the struggles of character growth and comes with a definite ending unlike any of the majority of the ongoing DC/Marvel century old never ending series.
Would be preferable if our protagonist starts out young, but even an older superhero would do. A focus on battles with realistic power scaling like the one in Invincible where the characters have fixed levels but also grow stronger with more training/experience would be great.
I feel like you’re looking for Manga my guy. Invincible is like a great lovechild between American and Japanese comics. It’s story and ideas are clearly Wester, but it adapts it in a Japanese story structure (Long running story with a teenage protagonist) and has a concrete ending. I recommend One Piece (Not finished yet), Hunter x Hunter (Also not finished) and Attack on Titan (Has some funny parallels to Invincible, but I won’t spoil it).