Strongest Survival by Otome Game’s Heroine (LN) - Vol 1 Chapter 5: Training Inside the Forest

He is an undead who is devoid of all humanity, he is the one and only supreme overlord, he is a man who has severe mysophobia.

There are many people who try to act cool in front of him, whatever soldier king, assassin, system user, transmigrator, reincarnator, the strong returning, the strong coming down from the mountain, person coming back from the immortal world, reincarnation of the devil king, immortal emperor possessing someone’s body, and so on, all of them do not know what will happen next

- Description from Novelupdates

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.

The youngest, silly fourteenth son of the Yan Emperor had reached the age where he should be given a separated territory now. He rejected the wealthy land, neighbouring the capital city, and instead chose the wildest land in the western region— Liangcheng. Everyone shook their heads and sighed. A fool is indeed a fool. If you go to Liangcheng, you will be killed by barbarians in less than three to five years.

One year later, the watermelon presented to the Emperor as the tribute from Liangcheng in the west was sweet and crispy. There was no one in the palace who did not love it.

Two years later, Liangcheng presented corn as a tribute to the Emperor. The yield was high, and the taste was good. No one in the country could resist liking it.

Three years later, Liangcheng defeated the barbarians and presented their prisoners in front of the imperial court. The people of Yan were excited and their morale was greatly boosted.

Four years later… Everyone said that the fourteenth prince Mingyu was a fool, while the little fatty Yu, who transmigrated with the golden finger, chuckled. Let’s see how you guys look at this fool build his own territory, then.

- Description from Novelupdates

At the beginning of the 21st century, twelve reincarnations shattered the void and returned to their hometown.

They preach the world and reopen the space of reincarnation.

Then……

“The Republic of East Asia announced that it will fully implement a five-year spell casting and twelve-year simulation mage training policy.”

“The Republic of East Asia has announced a new change in the marriage law, making it legal to marry someone you call upon after meeting the adulthood conditions of your respective race.”

“The Republic of East Asia announced that the East China Military Region No. 1 Mobile Armor Brigade was established, and the special humanoid mecha “Gundam” officially joined the campaign.”

“Congratulations from the United Kingdom on this, the upper hero Arturia Pendragon will visit Shanghai next month”

“In the far east of Japan, the ignition of the wave engine failed, or seek energy assistance from the East Asian Republic.”

“Space cracks have been discovered in the Chernobyl region, alien creatures have ravaged the Chernobyl region, and the Russian Defense Forces have entered the battle.”

Four years after twelve reincarnators changed the world, Li Ping entered his own battlefield for the first time.

PS: Although the introduction is like this… but in fact it is written about two thorns + machine battle + movie + mythical stew…

- Description from novelbuddy