Maou na Ore to Fushihime no Yubiwa - Volume 1 Prologue

I found a girl of unknown origin outside; she claims to be a time traveler from a post-apocalyptic era.Great calamity is imminent, with abominations spreading across the land, human civilization annihilated, and even the world itself shattering, all beyond redemption.As for myself,I am considering how to confine this beautiful girl, who has temporarily lost her powers, within my home.

Long Fei, a cross-timer and doujin, is an otaku who traveled to another world. In the original world, he was an otaku fan of Gundam and military science fiction.

He died in an accident and was reincarnated into another world. The Gundam works he had read before his death and the techniques in various military novels could be brought to another world.

How would he use the Gundam that Long Fei created? What waves can be caused in this different world?

- Description from novelbuddy

A thousand years ago, the Great Calamity struck Earth. Countless rifts tore through reality, opening portals between the Demon Realm and the Human World. Overrun by monsters, humanity was on the brink of extinction. But at its darkest hour, something miraculous happened—those who died returned, awakening strange new powers that allowed them to fight back.Vale knew that story well. Maybe that's why he wasn't surprised when he heard the voice of the system speak to him.[ Congratulations! You have died. ][ Your First Trial of Death begins now. ]What truly shocked him, however, was the question burning in his mind:“Who would dare to assassinate the Second Prince of Verythmia?”

When a traverser mistakenly thought that he had crossed the back of Britain in the 1980s, and when he was suffering from childhood, he would eventually sink into the darkness in repentance, and a strange and familiar admission notice would light up his life.

But when he came into contact with the deeper darkness, did he choose to stay away from the abyss or jump into it without hesitation?

”You wait, I will be back soon.”

On the fifth floor of the St. Mungo Hospital, he finally firmly held her pale hand.

This is a story of biting teeth, even a liar that you can lie, and struggles repeatedly in pain and tenderness.

- Description from Novelupdates