I Quit Being The Male Lead’s Rival - Chapter 149

She, a 21st century mercenary queen, had crossed over into a tragically betrayed body of a waste. Waste? She will show them what it means to be a waste! Betrayed? With the Ancient Manual in her hands, she will astonish all the despicable men and cheap women!

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

Crossing to One Piece world, he became Roger’s younger brother.

With one touch of the stone, Tyron receives his Class and his life changes forever.In an instant his bright and promising future as the scion of two powerful Slayers is torn apart and he must make a decision.Will he allow his Class to be purged from his soul, or will he cling to it, abandon all that he knows, and rise to power?