MTL - I’m Fighting Back In the Ninja World with Spells - Chapter 510 Day Tiger!

Civilization is destroyed and records lost. Only Dudian survives in a cryogenic sleep. Three hundred years later, Dudian wakes up and must become Dean to survive. Who can he trust in this world overrun by monsters without and within?

- Description from Novelupdates

Gao Yang was a military enthusiast, an ordinary one, who loved knives, guns, and adventure.In an accident, Gao Yang found himself in Africa, where he unfortunately experienced a plane crash. Although he miraculously survived, his life henceforth was one where he could only scrape by under the muzzle of guns, for he had become a mercenary.What heights could a military enthusiast reach in the international Mercenary World?Please, wait and see.

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!

…but it seems pretty doable.