As a Magnate, I Started Checking in at a Convenience Store - Chapter 14: The Palms Residence

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.

An ordinary young man on earth, Xia Feng, traveled to a world of sword and magic, and took the body of Lucien Evans, another ordinary young man.

Betrayed. Starved. Left to die alone in a world that chewed up the weak and spat them out.Gu Qingran trusted the wrong people, loved the wrong man, and paid the ultimate price.But fate? Fate gave her a second chance.Reborn 30 days before the apocalypse, she refuses to be the naive fool she once was. This time, there are no attachments, no kindness—only power.With the Omni-Alchemist System, she can create weapons deadlier than an arsenal, fortresses stronger than steel, and medicines that could cure or kill with a single drop.While the world slept, she stockpiled.While they wasted time..she built an empire. When the world burned, she rose from the ashes—untouchable, unstoppable and unchallenged.Let the apocalypse come. Let them beg for mercy.Because in this life, Gu Qingran is no one’s prey.She is the storm.

99 is one, and nine refinements are returned to Xian.

A young town boy, stepping on Xiuxian Road, is not a family, no gold fingers, with his own determination and wisdom, the nine major cultivation system, the nine realms step by step to the peak, and finally ninety-nine one, the achievement of true immortal.

- Description from Uukanshu translation