My Husband Is a Million Years Old Vampire - Chapter 80

【Welcome to the Love Simulator】【You can freely choose to simulate with women whose appearance rating is 7 or above (on a 10-point scale) and have basic connections to your reality.】【The simulation is entirely free; please explore on your own.】【After the simulation ends, the system will evaluate the results and provide rewards.】【Current number of simulations: 4】【The number of simulations is not fixed and can be restored through special rewards or the passage of time.】Wait—why are all the simulation targets such difficult-to-handle 2D female leads?

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.

After being reborn, Bella Green is determined to punish the scum, slap faces, and sing her way to the pinnacle of life. However, she is accidentally picked up by the person she least wants to see and taken home as a cheap 'brother.'Faced with the naughty yet particularly disobedient little Demon King, Mason Bennett sternly instructs: “No fighting, no skipping class, no dating!”One day, the little Demon King shows up on television in a stunning long dress, and Mason Bennett is furious, immediately tying her up and bringing her home for an in-depth lesson!!Looking at her suitors who were beaten up and unable to take care of themselves, Bella's eye twitches, what about the promise of no fighting?Being forcibly dragged out of the classroom and carried home by a certain jealous king while attending class, what about the promise of no skipping classes?Finally coaxed and deceived into the civil affairs bureau, Bella teared up, damn it, what about the promise of no dating!!!

Liu Yan, an ordinary office worker from Earth, unexpectedly traveled to a strange world.

The heroes of the ages are on the side, embarking on a journey to conquer the heavens.

- Description from novelbuddy