Danmachi: Clones System - Chapter 73 - Suspicion.

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.

When a mountain comes to life, awakening its consciousness, it takes on another form—a Mountain Spirit. And that’s me reborn with extraordinary Divine powers.Want to know what these divine powers are?Well, one of them allows me to accelerate herb growth—up to one hundred times faster! Impressive, right?But wait, there’s more! I also possess a ‘golden finger’—which is ‘Space-Time’ system that lets me fish for lost techniques, weapons, pill formulas, and other treasures from the rivers of time and space.With these at my disposal, I’m sure to become stronger, at least stronger than the beautiful sect master who claims my mountain as her personal retreat and constantly drag me into her matters.It’s not an easy life, but no need to worry! I’m not just any spirit—I’m a human spirit born from a mountain, which means I have an extraordinary talent for cultivation.To top it off, my system was generous enough to grant me a divine cultivation technique right from the start. There’s just one tiny problem: it’s a dual cultivation technique, and I need a partner to cultivate it.So, I had no choice but to convince the sect master’s stunning disciple to help me out. I mean, it’s not like I’m after her gorgeous long legs, her curvaceous thighs, or her… well, you get the point.I’m just a humble cultivator trying to grow stronger by any means necessary.If only she’d run into some trouble, so I could swoop in and save the day. That would make things a lot easier for me… but alas, life is never that simple.Still, I’ll find a way. With my Space-Time system, my mountain’s power, and a little charm, I’ll outgrow this mountain and surpass everyone—even the sect master. And maybe, just maybe, I’ll enjoy the beauties along the way.

While enjoying the favor of a handsome man, she learned that her country was ruined and her family was destroyed. What should a fallen princess do?Xiang Ying says, of course, she should use space to her advantage, empty the palace, and leave nothing for the enemy army!As the captain of a post-apocalyptic infrastructure team, she was thrown into a book by an explosion.The enemy army entered the palace, famine was impending, and she was encircled as a prisoner of war, taking care of three children.Such a catastrophic beginning made Xiang Ying exclaim, the good days are coming!Compared to the post-apocalypse, what is this?On the road to exile, while others suffered, she enjoyed melons. When everyone else was munching on dry bread, Xiang Ying and her children were savoring sumptuous meals.Everyone grew thinner, except for the three children who remained plump and cheerful, patting their bellies and saying wildly: Mother, we can’t eat any more, really!Xiang Ying, holding hot pot, milk tea, and roast chicken, enjoyed the scenery along the road, hoarding supplies as they fled, making life more flavorful.The villainess mocked her: What use is only having food? You're still a conquered slave!Xiang Ying pulled out the Imperial Jade Seal: Right, from today onwards, I will be the Empress.The enemy army was dumbfounded; she never said the thirty thousand wanderers she brought were elite troops!On the day Xiang Ying restored her country, the man who accompanied her through hardships held her hand.Jie Chen: For the sake of our three children, can we finally become official?Xiang Ying: Men should keep to their places, not seek a title.Jie Chen: ...With the country as my betrothal, my Jade Seal and my nation are all yours.Xiang Ying: Deal! Tonight's our wedding night!

When disaster strikes, all order collapses, money becomes meaningless paper, and discussions about order lose their significance. The only assurance that remains is power. And I, possessing power, can do as I please.In this post-apocalyptic world, besides growing stronger, Li Ming must also deal with the persistent neighbor who continually sends the wife to borrow food.“Ma'am, you can't always request food without offering anything in return, can you?”