MTL - Deep Sea Survival: Start a Submarine (Deep Ocean Survival: A Submarine From The Start) - Chapter 123 Arms company agent

Zhang Xuan traverses into a foreign world and becomes an honorable teacher. A mysterious library appears in his mind. As long as it is something he has seen, regardless of whether it is a human or an object, a book on its weakness would be automatically compiled. Thus, he became formidable.

“Emperor Haotian, why don’t you like to wear underwear? To think that you’re still an emperor, can you pay more attention to your image?”

“Fairy Linglong, if you continue to suffer from insomnia, you can always look for me. I have a way with lullabies!”

“You as well, Qiankun Demon Lord, can you cut down on the garlic? Do you want to stink me to death?”

…

This is an incredible story about the heritage between teacher and students, cultivating and guiding the world’s strongest experts.

At the end of the world, a legendary hero gave his life to save a dear friend, only to be reborn as a four-year-old orphan with 'Crab Affinity'.The apocalypse has come and gone, claiming humanity with it. All humans have had their 'Souls' stolen and claimed by monsters - vampires, demons, zombies - you name it.Reborn as Barnacles (Barns for short), the once-legendary hero claws his way back to strength under the tutelage of the gluttonous King Crab, a sentient crustacean with more vice than virtue in his shell.Follow Barns' journey as he rediscovers his power of rebirth, which when combined with a little 'crab magic' has the power to reset humans back to their original selves.It's time to take a crack at resetting the apocalypse.

To reward Meng Fan for his bravery before his heroic death, the cosmos rewarded him with a ‘system’, sending him back in time to three months ago, alive.

System, “You have a sickness. Moreover, you’ll have one in every world.”

Hao Ritian, “…”

System, “What’s wrong? Is there a problem?”

Hao Ritian smiled, “No, there’s no problem. I was just a bit excited.”

System, “…”

That smile intensified the system’s feeling of ominous foreboding. It has had this premonition since it learned the name of its host. Now it only prays that this is all its imagination!

Ps: Protagonist shou 1v1, the gong is always the same person.

- Description from Novelupdates