The Billionaire's Rental Wife Is A Hot Shot - Chapter 72: Shattered Hopes

Huang Dan’s pain nerve is innately different from the ordinary people. A little tore in his skin can cause him to sweat all over his body painfully to the point of him unable to make a word out.

Somehow, he began to cross world, following Mr. System to do the tasks…

In the first world, Huang Dan realizes what it means to die painfully and to live to die again.

TL’s summary:
MC suddenly transmigrated and is bind to a system, requiring him to solve mysteries. Born with a higher degree of pain sensitivity, he met different people in the different worlds and learns what kind of emotion smiling is.

- Description from Novelupdates

Yuan Luoyi felt like she was a little hamster in a pit of snakes, with her family full of crazy villains, yet as the fake heiress she still focused on slacking off.

Dad was an arms dealer, Mom an ace assassin.

Eldest brother, business world’s killing god, with proxy syndrome.

Second brother, cold-blooded lawyer, zero moral sense.

Third brother, addicted to killing, born with antisocial personality.

Fourth brother, evil celebrity, who trained fans into believers.

Fifth brother, genius scholar, loves those pure white bones.

Yuan Luoyi didn’t know that because of her birth, the world gained five more brothers, not five more lunatics.

Those greedy villains also didn’t know, the one they wanted to kill was not an ordinary girl, but the most beloved little sister of five crazy bastard brothers.

The female lead has 99 lifetimes of memories, a system, harem darling + suspense, happy ending.

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.

The strongest King of Soldiers returns to the city of flowers, becoming his fiancée's cohabiting bodyguard!