I Became the Academy's Pink Airhead - Chapter 126

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

A hero must be compassionate, selfless and courageous.But that isn't all. Because a hero must also be powerful.In this world, power is everything. Strength decides who gets to save lives and who's left with community service. That’s why I was nothing — a rank 50 E-Class reject, skating through the streets, saving what little I could while the real heroes battled gods and monsters.Then one day, I died. Almost.Dragged into the abyss, I was given a second chance: the Forever Core. An armor that evolves. A system that never stops adapting. Every battle, every hit, every mistake, I come back stronger.Now, the monsters that once crushed me can’t kill me the same way twice.I must adapt. Evolve. I must grow stronger and fight harder. Because humanity is worth fighting for.Even if I have to burn every villain alive to prove it.

Waking up, Kim Hajin finds himself in a familiar world but an unfamiliar body.

“If I don’t die… I swear I will act on all my evil thoughts..”

Not exactly everyone’s typical thought when they’re about to die. What will a cowardly young man do when reincarnated with the evil powers to redefine his destiny? Can the natural kindness of human nature triumph over evil? Will he become the cold-blooded demon king of legend, or will he forge his own path and rain down another kind of terror?

- Description from novelupdates