Transmigrated As My Former Uncle's Sweetheart - Chapter 931 - I Was Just Helping You Out Of Pity  

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.

Shen Dong's marriage proposal failed, and he was dumped. That night, he was taken away by Chen Yuyan. When he woke up, Shen Dong found Chen Yuyan lying beside him. He was instantly dumbfounded. What made him even more confused was that Chen Yuyan actually said she liked him! And she had liked him for a long time!Chen Yuyan said, “Shen Dong, I want to be with you, but if you don't want to, I won't hold you responsible.”[Ding! The Ultimate Winner System is activated. The host currently has two options regarding the situation at hand.][First option, not taking responsibility for Chen Yuyan and pretending nothing happened, getting a reward of ten million yuan.][Second option, going to the civil affairs bureau with Chen Yuyan today to get married, getting a super gift package reward.]Holy crap! Holy crap!A cheat that could change his life had arrived!

Jack transmigrated to a parallel world and locked on to a Judge System that provided rewards for punishing evil. Hence, an Adjudicator of Death who stood above the law was hence born.