Penitent - Chapter 198 Book 3 Ch 42: Enemy’s Enemy

Traveling into the world of Genshin Impact—and of all places, ending up in Snezhnaya, which hasn’t even been released yet.A catastrophic start… but luckily, he received the gaze of an Aeon.With a single punch, he shattered a Fatui Debt Collector.With three punches, he brought down the Captain.As the knight’s helmet in the Captain’s hand crunched beneath Su Ran’s palm—The voice of the Tsaritsa rang out in sorrow:“Please… spare him.”Su Ran smirked. “Beg me?”The Tsaritsa whispered, “I beg you… please, spare him.”Looking up at the familiar figure upon the throne, he finally loosened his grip.~-------visit my pa treon for 30+ advanced chapters:pat reon .com/YonkoSlayer

Struck down amid the battle, the Hero and Demon King meet their demise. As their souls linger on the edge of the afterlife, a mysterious force intervenes, merging their fragmented souls together with a new being. Rusty, the living armor, now affected by their memories and presence, embarks on his own quest. Will he seek revenge on those who betrayed the hero, or will he fulfill the desires of the fallen demon king? or instead, forge his own path?

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 Ziqiao woke up from her deep slumber to find herself transmigrated as the character of an ancient novel. To make matters even worse, she was written by the author to be the moronic daughter of the villain, merely a walking cannon fodder.

“Are the Gods punishing me because I left a bad review?!”

Yet it doesn’t end there; she has to strive against a reborn heroine’s revenge! And especially against the major death flag in the plot: getting married to the capital’s fool.

But why does she find this fool’s eyes to be too cunning?

- Description from Novelupdates