Baka to Test to Shoukanjuu‎ - Volume 9.5, Me and Tsuchiyas House and an Unshakeable Heart

After her rebirth, she stared at her drop-dead gorgeous husband and suspected that she must have struck her head hard at the door for demanding a divorce time and time again!

In her previous life, she was blinded and murdered by her blood relatives. Now that she was reborn, she vowed to hold on to this thick thigh of her president husband, ravage her enemies, tear down that white lotus and regain her happiness.

- Description from Novelupdates

Chen Rui, an otaku from earth, is reborn into a human body in another world, who falls into the legendary evil, brutal world of the devil called Mozu where humans are treated as food. He has to survive while facing horrors of the devil, violent dragons and a variety of power enemies depending on a strange super system chip and his wits. Surrounded by Devil’s beauties such as black-bellied lolita princess, cold queens, violent dragons, charming poisonous devils …

Wanting to live in the Devil’s world is hard! Wanting to live in the Devil’s world as a human is harder! Wanting a human to be the devil’s son-in-law is hardest!

Let us see how a small otaku uses power and strategy step by step starting from an ordinary human to writing a legend as the devil’s greatest son-in-law.

- 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.

Once the ultimate Soldier King and a supreme assassin, empowered by a magical Magic Bracelet, had mastered Cultivation, Medical Skill, X-ray vision, and foreseeing the future… became an omnipotent master of pretense. Come, come, come, watch the omnipotent master of pretense teach you a few tricks of pretense.A demonic man who walked out of a major foreign prison, yet married a cold Queen-like CEO wife, leading a life where “you glare at me with displeasure, and I look at you with disdain.”