Any good manga/manhwa with op main character?

Gods of High School - main character joins a tournament and is classified as low level but surprised everyone with his kicks. He turned out to be a god.

Black Haze - a webtoon (art and story improved after chapter 20+) where the main character is the number one magician but is forced to attend a magic school (undercover mission). He's so cocky and pretends to be weak (to no avail) and surprises a lot of bullies and teachers.

Magician - a 400 year old magician is accompanied by two kids in his journey to undo an imortality spell. All three are overpowered after the 9year time skip.

The Breaker - teacher is a master in martial arts. A weak student wants to get trained.

Flow - everyone is born under a spirit and main character was under the cat's. He gets treated poorly but then his cat turned out to be one of the four legendary spirit, white tiger. He wished to turn back time for one day (his birthday) and ends up killing the love of his life.

One Punch Man. A guy who is a super hero for fun who can take out enemies with one punch.

Bleach. The main character ends up being a soul reaper (essentially) and somehow always saves the days.

Fairy Tail. A guild's strongest team who somehow manage to defeat everyone and destroy everything.

Hellsing. A chick owns freaking Dracula.

Problem Children Are Coming From Another World, Aren't They?

No, that's not a joke. That's the English name of the manga/anime.