MTL - Steel Shell System - Chapter 18 Repeated killings

The world is a place full of mystery, and many ordinary people live their entire lives without ever glimpsing even one percent of its truth.The fate of one family was destined to be average until one rainy night, when a family member arrived at the newly married couple's door with a child born out of wedlock.Terra was about to undergo an upheaval because... the strongest was born!---------------------This is the story of Kaizer Lunin, a young man born with a special ability that causes him to suffer from mild antisocial personality disorder.A brush with life and death awakens this power fully, turning him into one of the strongest Espers in the world!However, this also thrusts him into the hidden parts of the world, where secret societies, powerful factions, and the government clash in their bid to claim the empty title of 'strongest Esper'—a void left by a certain someone.And maybe, if he doesn’t die prematurely, Kaizer has a shot at that title himself!

Haruka, consulted by a friend who ran into a ghost at school, goes to the Movie Research Circle to see a man with mysterious powers. However, the person who meets her there is an affected young man with terrible bed hair and sleepy eyes. What does Haruka consult him about? A confinement and murder case at a women’s university, a false suicide case… The great detective who can see the spirits of the dead, Saitou Yakumo, takes these cases on in this astoundingly high-speed spiritual mystery!

Once through the pirates, Lu En became the son of Monkey d Dragon, a grandfather named Monkey d Karp, and an unreliable and neurotic younger brother named Luffy.

Fortunately, the ghost back system is activated!

The completion of the ghost back is 10%, and the training effect is increased by 100 times!

The completion of the ghost back is 20%, and the training effect is increased by 1000 times!

…

One day, Lu En, a ghost-backed master, appeared in front of Luffy who was shouting to go to sea, and made Luffy cry on the spot.

Luffy: “The pirates in the sea are all monsters like my brother? I don’t want to go out to sea!”

Garp: “For a long time, the two boys, Long and Luffy, with small arms and calves, I really doubt that they are not my sons and grandsons. Like Lu En, they are the grandsons of the old man!”

Warring States: “The strongest creature in the sea, land and air is Kaido? No, it’s Lu En!”

- Description from novelbuddy