Becoming Immortal Through Getting Married - Chapter 343 - : Falling Out and Turning the Table

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.

A world where mana density was extremely abundant. Because of that, the world connected to a special place through an ancient gate—the World of Beasts. Through this connection with beasts, mankind became superhuman, wielding power capable of tearing apart sky and ground.However, too much of anything is never a good thing. Countless dungeons appeared across the rifts… and demons.Rocky Stephens, the first son of a Great Clan, the reincarnator, carrying memories from another world.… yet also a useless piece of trash. No one even remembered his name. His parents died. Betrayed by the branch clan, his beast was killed. He lived in a phase he had never dreamed of—a nightmare.When a second chance came, he returned to the World of Beasts… and awakened a system that could see through all Beasts’ training paths!With the system, his beast could level up like the wind… it could learn and upgrade its skills on its own, and even more.

The Chaos War, a time when even the gods fought for survival, was an unexpected and cataclysmic event. The reasons for its occurrence remain shrouded in mystery, and in the new era, all traces of the world before the war have been erased from existence.The universe, the immortal realm, and even the domain of the gods were all affected, and no one was spared from the aftermath of the conflict. The beings who lived before the war are now known as ancient gods, and their legends continue to captivate and inspire the people of the new era.Chen Tian, who was killed due to a treasure from the ancient era, finds himself reincarnated in a strange and unfamiliar place known as Earth.Unlike his previous life, the people here are only mortal and rely heavily on technology for their daily lives, and the concept of cultivation is unknown to them.Thinking that he would have an easy life in this new world, Chen Tian quickly realizes this world is far from simple.Join Chen Tian on his journey in discovering mysteries that will leave even gods shocked, and witness how he becomes a powerful cultivator, fighting against immortals and gods.