One Piece: Human God - Chapter 14: Yukiryu Island Battle III

Kurogami Ichiro was desperate because he couldn’t achieve what he wanted when he once started his martial arts path at age of 8!

Magnus was reincarnated in a magic world. He led a simple life on Earth and that was something he liked rather than being dragged into conflicts or into adventures to save the world or something like that.He never cared to be the MC but hoped that he would have a pleasant life, much better than his previous life.Whether he could or not, read the tales to see.

I exist in the darkness, disappear under the bright light, and will eventually devour the sun and turn into the shadow of all things… Known by people as the indescribable terror of darkness; the king of shadows; the dark day; the existence of the shadow of the world , is still just a somewhat special high school student, facing a weird death game…

- Description from novelbuddy

Lucien, a guy who has nothing but the desire to save his mother. To get strong enough, he makes a contract with the demon of L.u.s.t. And now, only by making a great harem, will he gain the power to protect those dear to him.