Steel, Guns, and the Industrial Party in Another World - Chapter 348:

In the Dragon Abyss Empire, nestled within Clear Water Town, young Jiaang Lin awakens from a brutal beating by his cousin Jiaang Ren, only to discover he has been reborn into his younger self. Once a mocked disciple with blocked meridians, Jiaang Lin had risen to greatness in his past life as a prodigious warrior and Pill Saint. Now, with a second chance, he vows to protect his loved ones and conquer his enemies. How will Jiaang Lin change his destiny and ascend to the pinnacle of martial prowess once more?

Under the vast immortal sky, the brilliance of an era is nothing but fireworks blooming at the fingertips.

Overlooking the earth, for thousands of years, life and death, where are they all? The Immortal Gate, the Dynasty, and the Supreme Holy Land are all just a handful of loess under the Immortal Vault.

A thousand years of splendor, and a smash into ashes.

Cinders sprout in the depths of the ruins, and you and I strive to be the trees that reach the sky.

What the hell is on the other side of the Immortal Firmament?

- Description from novelbuddy

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