The CEO's Knight in Shining Armor - Chapter 43

Magnus was reincarnated in a magic world. He led a simple life on Earth and that was something he liked rather than being dragged into conflicts or into adventures to save the world or something like that.He never cared to be the MC but hoped that he would have a pleasant life, much better than his previous life.Whether he could or not, read the tales to see.

She, the “godly doctor” of an assassin organization in 21st century, transmigrated into the body of Yun Family’s abandoned, good-for-nothing Ninth Miss. Good-for-nothing? Then she’ll let the world see what a real good-for-nothing looks like. Summoners are legendary? Nothing is impossible in this world! She’ll become the first Magical Summoner.

He, the third prince in Long Xu Kingdom and the mysterious, behind-the-scenes owner of Zhou Dynasty’s monopolized business, seemingly handsome and uninhibited, is actually brutal and merciless.

The world knows her as a sickly good-for-nothing and her standing is as low as a servant’s, yet she solely dominates his heart. Trickery, schemes, overbearing, seducing… an exhaustion of methods, all to capture her heart. The scheming couple supports each other, producing stories about enmity, love and win-win cooperation.

Read to see how they stand side-by-side at the peak of this extraordinary world.

- Description from Novelupdates

Shuu is a member of the literary club that can’t write. One day, he gets a mysterious message on his phone from a girl called Eina, and from that impulsive contact, they begin to exchange messages. They talk of things like their shared interest in novels and grow close. However, when they try and meet, they discover a shocking truth. Eina lives… not in the present, but five years in the past! How will their love develop, parted by five years of nights…!?

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.