Warrior Training System - Chapter 16: Introduction to Mana

A supreme expert in the Immortal World had died, and a strand of his soul returned to its original body on Earth. Tang Xiu discovered with amazement that ten thousand years passed in the Immortal World, yet only a single year passed on Earth.

Ruthlessly betrayed by his lover and trusted friends, Tang Xiu found that his soul went back to his previous body on Earth, and, despite he spent 10,000 years in the Immortal World, just a year has passed on Earth and many things have changed. Having an unsurpassed knowledge, Tang Xiu will protect his loved ones and go back to the Immortal World to take his revenge.

- Description from Novelupdates

I’m a high school student who became an author after debuting at Dengeki Bunko. After taking a year of hiatus from school to write my work, I transferred out to another high school to study, and met a girl called Eri Nitadori in school, a rookie voice actress cast as a character in the anime adaptation of my work.

In school, we treat our professions as a secret. However, Nitadori’s very popular in class, and I’m a loner…the only chance we get to talk to each other is when we take the Limited Express train together every Thursday, seated side by side as we head off for an anime, After Recording.

To improve her skills, she asked me questions regarding the profession. While I was answering the questions regarding the process–how did it end up like this.

This is what I last remembered before I lost consciousness, and the story of my near-death experience.

To save a doomed fantasy world, I killed the main characters, then destroyed the game world, and fell into another timeline as the academy's top seat and rival to the protagonist.Now, I'm trying to save the world and steer it towards a better ending…But I'm the final boss.

some day.

The heavens and worlds shook.

A huge list appeared in the sky, and the scene of counting the strange nicknames of the heavens began.

Inventory tenth, head pillar Tanjiro

Inventory Ninth: The God of the Earth Cannot Fly (Gulardo), the God of the Sea Fathead Fish (Kioka)

Inventory eighth, the second of the four Uchiha laughs – Uchiha Madara, Uchiha Obito

…

After the video is posted.

Countless dimensions were shocked.

It turns out that there are so many people with weird nicknames in countless worlds.

- Description from novelbuddy