In the Second Generation of the Trench, He Changed To the Ruanfan Script - Chapter 44:

Reiji Saeki, who lives in the north eastern countryside town, lost his life in an accident during summer vacation. ……But before he knew it, a mysterious ball of light hovered in front of his eyes in a world of whiteness. That ball of light was a magician from a parallel world, and is looking for a person qualified to inherit the magic they had created to prevent it from being lost. Reiji, who rode on that suggestion, now lives in the parallel world Elgin, with a new body and powerful magical power.

During this chaotic era, the darkness engulfs all.
In a struggle of fire and death, despair shrouds the continent.
The line between fantasy and reality becomes blurred as a speckle of starlight penetrates the night sky.
But is it enough to reverse the downfall and fate? To regain the lost glory?

Rhode is a famed player in the game “Dragon Soul Continent”. There, he leads the strongest player guild in the game, the Starlight Guild. Just as he defeats the last BOSS, the Void Dragon, he unexpectedly awoke in a world identical to the game.

As the Summoner Swordsman returns to the continent, waves will be cast in the rivers of fate. Can he face the coming chaos and avert the destruction of the continent?

- Description from Novelupdates

On the desolate barren planet of Rennes, an Asian teenager named Lin Yuan receives an admission notice for the Empire’s best military academy San Romia. So begins his life changing military school career.

There was a mysterious old man who approached the failed swordsman with the “100 million years button”. A magic button which can achieve the same effect as training for 100 million years if you push it.

The failed swordsman who pushed the button had his doubts, but immediately felt tremendous power rising in his body. So he pushed the button many times.

However it was a cursed button. The moment it was pushed, he was confined to the 100 million years prison of time. The first 100 years were devoted solely to training. After 1000 years he had forgotten why he swung his sword. He stopped thinking completely after 10,000 years had passed. After 100 million years he became crippled and finally managed to return to the real world. At the same time losing all his memories from the past 100 million years, the only thing that remained were his sword techniques. “I can become stronger just by pressing the button!” or so he thought and pushed the button many times after that. Foolishly trapping himself in that 100 million years of hell each time.

As he continued this loop, he began to think “If I destroy this world, will I get out of here?” A few billion years later, he finally escaped from the loop.

This is the story of a failed swordsman trying to make a name for himself in the world.