Mountain Sitting Immortal - Chapter 124: Black Mantis.

Qin Yichen returned to his youth with his memories of more than 10,000 years. Superb mental strength, advanced elixir formula, advanced martial arts.

- Description from xbiquge

Yuki, a high school junior, dies heroically saving a stranger and is reincarnated in a fantasy world, where he discovers an extraordinary and unrivaled power.

Leon Cromwell was hit by a truck and died. He thought he would never open his eyes again, but when he did, it was not what he expected.

“What? Black bones?! What's going on? Where am I?!”

He had been reincarnated into a world of magic and war! With his new situation, Leon had to find a way to get strong quickly and be able to hold his ground against the countless enemies that will come his way!

Follow the black skeleton, Leon, as he explores this new world, makes friends, finds love, and gets down to the bottom of his sudden death.

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