This Human Immortal Is Too Serious - Chapter 476 - 474: Young man, is this unparalleled secret manual yours?

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

In a post-apocalyptic world where humanity survives in fortified cities, only a lucky few awaken Talents, supernatural powers that allow them to level up.Isaac believed he was destined for an ordinary life—until he awakened the Bonded Blessings System.This system granted him a unique ability: he could share the talents, abilities, and progress of his wives.[Your wife, Sword Empress, has reached Overlord rank. Sharing progress…][You have leveled up 10 times and reached Overlord rank!][Your wife, Ghost Queen, has unlocked the full potential of her Nether Eyes. Sharing progress…][You have awakened Supreme Demonic Nether Eyes!][Your wife, Dragon Saintess, has purified an Ancient Dragon Heart and absorbed it. Sharing progress…][You have awakened the Ancient Dragon God's Bloodline!]Killing monsters? Grinding for levels? Why bother when his wives could do it for him?As long as they grew stronger, so did he!

2029 was supposed to be the year humanity moved forward.Instead, a failed military experiment tore open a gate to another dimension unleashing creatures that could shatter mountains with a single strike.From the wreckage, a new era began. Technology forged from energy crystals found beyond the gate and soldiers wielding beast infusions fuels humanity’s last defenses.Soldiers, mercenaries, and the desperate are sent to hunt the beasts... and one day, to face the terror that waits Beyond the Crimson Gate.But every step closer to the gate brings one truth into focus. What waits on the other side may not be killable.

Seventeen-year-old Hajime Nagumo is your average, everyday otaku. However, his simple life of pulling all-nighters and sleeping in school is suddenly turned upside down when he, along with the rest of his class, is summoned to a fantasy world!