Reincarnated as a Son of the Sword Saint and the Sage - Chapter 41 41: Dungeon

Li Changlin, the underdog, was a small-time anchor who, by chance, acquired the Divine Tycoon Development System from Earth, and thus embarked on an awesome journey to become a life-achieving tycoon.

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

In a world where dungeons loom like dark secrets and monsters stalk the land, Rem’s awakening shattered the status quo. A surge of raw power flooded his veins as the Monster Monarch System bound itself to him, unlocking a terrifying potential.Each heartbeat echoed with the promise of countless souls waiting to be absorbed—skills, abilities, and monstrous strength ready to be claimed.Fuelled by an insatiable thirst for power, Rem set out on a deadly quest, driven by one singular goal: to rise above the chaos and stand at the pinnacle of the world. With nothing but the deadly abilities granted by the System, and a burning will to crush any who dared stand in his way, he carved his path through savage lands and ruthless mages.The hunt for strength never ends. The battle for supremacy has only just begun. Rem’s eyes are set on the throne of the Monarchs, and the Monster Monarch System will ensure nothing stands between him and his destiny.The grind was eternal...

In the world of the gods, everyone is a god, develop believers, gather faith, and lift the kingdom of God into the starry sky.

The young Xu Luo came to this world and started the Zerg dominance system.

Ding! Extract the sawgrass gene, and the springtail + sawgrass becomes a mantis insect!

Ding! Extract the snail gene, and the beetle + snail becomes a beetle.

…

Face Huggers + Angels + Dragons + Power of the Ancient Gods become Leviathans!

Extract the genes of all creatures, and the Zerg army sweeps the world!

(Book Friends Group 682275028,)

It can be updated on the shelves, don’t worry about eunuchs

- Description from novelbuddy