MTL - Hunter × Hunter: The Seven Deadly Sins - Chapter 734 One V Two

Ding Ning was just an ordinary youngster from a small border town in southwest China, but he had learned tremendous medical skills from his masters since his childhood. After graduating from college, he stayed in Ninghai City and tried to seek a job in a hospital there, but things did not go well at first. However, he accidentally saved Shen Muqing who was from a rich and powerful family, and then got involved in the confrontation between Ninghai special police team and a mysterious organization called Vampire Mercenary Group in order to protect Ling Yun who was his landlord’s daughter. It became the turning point of his life. After that, he started an incredible adventure during which he would find out the real identities of his father and masters and discover the secrets behind the mysterious organization Vampire Mercenary Group and the special weapons and tactics team Dragon Soul…
The story tells about how he opened nine apertures, fought with rogues, chased after various pretty girls and established a rich and powerful family by himself. He climbed up to the peak of his life step by step, and finally became medical sovereign.

- Description from Novelupdates

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

Shen Ningning died of exhaustion after being dared to run a marathon. She transmigrated into a savage, unfamiliar world where humans struggle to survive among beasts. Before she could despair, she discovered she was bound to the Peak Body Survival System.The system believes survival is nothing more than physical training. Hunting, fleeing, gathering food, and even fear are all treated as endurance tasks, with failure punished mercilessly. Trapped in a dangerous world and forced to follow the system’s rules, Shen Ningning can only struggle to survive one day at a time.Her situation worsens when a powerful snake beastman claims her as his mate and refuses to leave her side. As danger closes in from both the wildlands and the system itself, Shen Ningning must find a way to live in a world that demands strength—whether she is ready or not.