Citadel for All: The Only Unit Angel at the Start of the Game - Chapter 547

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

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?

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.

Ukei Kaito fought a desperate struggle in order to fulfill his role as a summoned hero. He defeated the Demon Lord and saved the very world, only to meet an end filled but with betrayal. The companions that he’d trusted throughout his journey betrayed him and killed him by sticking a blade through his chest.