From A Stronghold NPC To The Final BOSS - Chapter 1095 - : The nine tribulations

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.

【 Warning: Mature Content R-18 】Graves lived a content life, until he lost it all. After inheriting a hotel and immortality. As his final act, he sacrifices himself to save a woman's life.To his surprise, he reawakens to find the woman thanking him in an unorthodox way.His once normal life changes with this new power, and by comical chance, he throws himself into deadly situations to save women from bullets, blades, fire, planes, tanks, and trains.His new life is one of pain, except he always ends up on top.Join Graves on his comical struggle through the unnatural disasters he faces for the sake of his love life.

The mortal body, metamorphosis, longevity, immortality, and eternal life. These five realms, step by step, reveal themselves in front of you. As a normal person, how can one try step by step to reach and open the door to eternal life?

Between the heaven and the earth lies the mortal body, the mysteries of metamorphosis, freedom of longevity, the power of immortality, and the hope of eternal life. A story filled with endless new magic, a new world of immortal styles, people, demons, gods, fairies, magic, kings and emperors. A world of love and hatred, revenge, and mystical battle, all in “Eternal Life.”

Framed by her so-called best friend and half-sister, Su Qianxun stumbled upon a strange man when she was making her escape. A strange man so handsome it looked as if his face was carved by the Gods, but with a heart as cold as stone. A wild and fiery night ensued, and ever since then, they embarked on a journey filled with passion, lust, conspiracy and treachery.