I have Been Reincarnated! - 069 – Cast Aside Shame When Traveling (First)

It was a dangerous era. Extraterritorial ferocious beasts occupied 90% of the living space in the world, while humans could only survive in a small space. Fortunately, some of the surviving humans awakened to genetic martial arts! Breaking the shackles of one’s genetics was the foundation of cultivating martial arts. Lin Feng, who was born with congenital disease, could not experience a breakthrough. However, by some fateful encounter, he awakened to the ability to merge genes.

Beast Taming: I Can Evolve Indefinitely

Haruka, consulted by a friend who ran into a ghost at school, goes to the Movie Research Circle to see a man with mysterious powers. However, the person who meets her there is an affected young man with terrible bed hair and sleepy eyes. What does Haruka consult him about? A confinement and murder case at a women’s university, a false suicide case… The great detective who can see the spirits of the dead, Saitou Yakumo, takes these cases on in this astoundingly high-speed spiritual mystery!

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.