Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 5 - Intermission: The Work of Manager-san

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

To survive, the unfortunate Gong Qiying, who became the lord of the Sein Dungeon, had to make his dungeon extremely “hellish”:Doors that “cannot be opened from this side”,treasure chests “triggering teleport traps”,a three hundred and sixty-five mile journey from the starting point to the BOSS room with no place to rest,monster knights with great bows on either side of a narrow bridge,and sinister ambushes around corners.There's also unavoidable visits to poisonous pits and hidden paths...Additionally, well-known fighters like Isshin Ashina, the Furnace Knight, Rajang, and the Scourge Legion bring unexpected surprises!Various unique rewards such as the Flaming Sword, Murky Hand Scythe, Rapid Slash Longsword, Sacred Oath, and Flame Empowerment will make you too happy to contain your joy!Gong Qiying: The most important thing in my dungeon is to ensure adventurers have fun!

Kurono Maou is a high school student who is sensitive of his sharp eyes and bad expression. No girlfriend but gifted with friends in his own way, he had been living a peaceful life.

Genius, antisocial, solitary, intractable , maniacal.

At the turn of every era, it is he who raises the flag of the rebel cross.

Winners take it all, losers take the fall.

He who brings order to a chaotic world, assembles talents and masterminds.

He who hides among the crowd, yet stands on the top of the world.

— The one and only, him.

- Description from Novelupdates