Toaru Majutsu no Index - Volume 1, Chapter 3: The Grimoire Peacefully Smiles. "Forget_me_not."

Li Quangqing traversed to the cultivation world and became a family fisherman, starting with twenty acres of fish ponds.Unexpectedly, every time spiritual fish were harvested, a reward orb could be obtained.[Harvested one adult big green fish, received a lower-grade water arrow talisman!][Harvested one adult iron bone crab, received the “Gengjin Sword Technique”!][Harvested one adult longevity turtle, received the “Gui Sui Shou” pill, prolonging life by twenty years!]...Since then, Li Quangqing watched the tides rise and fall in the world, the wind and clouds changing, wanting only to raise fish and become immortal peacefully.Until thousands of years later, a certain Water Virtue True Immortal appeared out of nowhere, shaking the immortal realm, capable of covering the sky with one hand.“Since the Milky Way is also a river, it's okay for me to use it for fish farming, right?”

In the Realm of the Gods, countless legends fought over a mysterious cube. After the battle it disappeared into the void. Lin Ming stumbles upon this mystery object and begins his journey to become a hero of the land.

Lin Ming, a talented man for martial arts wanted to audition for Tian Yun Wu Fu with a girl named Lan Yunyue,
She was his childhood friend since young and they both have a small crush on each other.
But on the day of audition, Lan Yunyue did not come, which left Lin Ming in curiosity.
He later found out that a guy who is rich and talented, named Zhu Yan helped Lan Yunyue.

In a world where strength determines one’s future, William, an orphan with no extraordinary talents, faces a grim destiny—until a brutal attack leaves him clinging to life. Instead of death, he awakens to a mysterious and powerful entity lurking within his mind: the Shadow System, a game-like interface that promises him unimaginable power. But this power comes with dark secrets, and refusing it would mean his death. Forced into a pact with a voice that can hear his every thought, William must navigate a dangerous new reality where shadow abilities and celestial power collide. As he enters the prestigious military academy, his newfound abilities draw both allies and enemies, all while a deadly conspiracy brews in the shadows. With the odds stacked against him, William must unravel the mystery of the Shadow System and decide whether to embrace the darkness within—or be consumed by it. His journey from a bullied outcast to a potential god will challenge not just his survival, but his very humanity. Power always comes at a cost—will William be able to pay the price? “What am I?” William asked the system. The system’s voice echoed in his head, cold and indifferent. “You are nothing.”

This novel is also known as 1000 Years Later, Even My Weakest Follower Has Become A Demon King

After traveling through the game where he worked so hard to clear the level, Zhou Mu found that the whole world was stunned for some reason.

Why is the mainland united in its own name?

What’s going on with this religion in its own name?

What the hell are members of the royal family claiming to have their own bloodline? I wonder if this game doesn’t have this feature?

“What have you done in the thousand years I’ve been away!”

- Description from novelbuddy