Counterattack System appeared when I'm already At The Mahayana Realm - Chapter 188 - 187: Nine -Turn Immortal Pill

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.

(A/N: If a ruthless MC is not your cup of tea, don't read this.)Heat Wave, Torrential Rain, Severe Cold, Tsunami, Flood, and Alien Beasts swept the world in a series of natural disasters, almost wiping out mankind.Lu Nanzhi regressed two years to the past and found out that the settings of the natural disasters was similar to the mobile game app she played before regression.And it was in the beta testing phase.Ding—[Beta Game Test is over.][Data is being reset.][Player is starting over.][Please claim the Beta Test Rewards.]Equip with the Beta Test Rewards, Lu Nanzhi was determine to survive in this life and started stockpiling like crazy!

【Host, host! I might be late, but I, the Femme Fatale Conquer System, am here to accompany you!】

【Now, let’s first conquer Momoana, a legendary female emperor who boasts looks and wits.】

Shu Yichao: “Charge, my nomads! Show them our unrivaled archery!”

And so, Momoana died.

【My host, I’ll assume what happened earlier was an accident. We have to succeed for the next one. Our next conquer target is Purin, a lofty and cold sorceress.】

Shi Yichao: “Clear the mobs and stack skeletons! I shall bring the undead calamity upon the world!”

And so, Purin died.

【…Maybe you didn’t hear me clearly, my host. I said court her, not cull her. Our next target–】

Shu Yichao: “Build the hive and spam the worms. My hive mind shall devour the world! Who can compete with me?”

【…】

Shi Yichao: “Halleluyah! I have finally gotten rid of every single one of them! Speaking of which, System, it has been a long time since you last spoke to me?”

【I’m tired. Just go and destroy everything.】

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