MTL - Doomsday Commander - Chapter 8 ferocious

Shao Ci was bound to the ‘Befriending the Most Powerful Person’ system. After crossing through, only then did he discovered that as long as a more powerful person emerge, this unscrupulous system will immediately change the ‘capture’ target….

- Description from Novelupdates

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

The story is about a man whose compulsive tendencies make it impossible for him to keep a job, and a young girl who skips school and loves insects. The two meet, come to support each other in reintegrating into society, and fall in love. There’s a problem, however: namely, the parasites in their heads.

A mortal youth accidentally stumbled upon the path of immortality and struggled to move forward on the arduous journey of seeking immortality.The road to immortality is more difficult than reaching the heavens, yet despite the countless obstacles, his determination to pursue immortality remained unwavering.Looking back, the green mountains still stood, but his old companions had all turned to bones.