MTL - Hello, Heir - Chapter 74 I ca n’t tell Si Zhengting about this

Violet skies, a world undergoing massive changes, a deficient moon, interlinking voids…
When the world experienced a cataclysmic event,the majority of living things ceased to exist. Although humanity survived by hiding in the last safe zones, humans had to face mutated dire beasts and colossal source beasts that could break through the space barrier and enter the earth at any second.
Luo Yunyang, a young man who grew up in those calamitous times, obtained an attribute regulator and set out to walk the path of supremacy!

- Description from novelupdates

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.

Bibi Dong, once the powerful Supreme Pontiff, never expected to be reborn—especially not as someone else's martial spirit. In this new life, she finds herself bound to a young soul master with great potential but little knowledge of the powerful spirit within him.As Bibi Dong guides her host, she must confront her past mistakes and figure out why she was given this second chance. Is it to correct her past, or is there something more at play?

Have you ever thought a monster that has a job of a summoner and a tamer

what should it call itself Monster Summoner? Monster Tamer? but he itself was a monster too

Watch as our mc travels the world as an reincarnated human who turn into a monster