The Novel’s Villain - Chapter 0.13: Prince

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.

She had a lifetime of fake virtue without receiving a virtuous ending. In the next lifetime, she controls fates with the flip of her hand. To the jerk who wasn’t faithful, she’ll draw a premature death talisman for him. For the poisonous step mother, she’ll send a death flower. For the step sister who is two faced, she’ll personally rip off that fake pretty face!

But when she personally offered up her body to her nemesis because of a child who she had no fate with, something unexpected happened. The night of the big wedding, the groom changed and a cold and luxurious man pushed her down. “You can marry whoever you like, but you can only give birth to my children!”

- Description from Novelupdates

Alex, a young man with ambition but unfortunate life.He grew up as an orphan and from a very young age, learned to stand on his own feet.Barely making a living by searching through the dumpsite for things that could be sold.One day, when he came back home from the dumpsite, Alex decided to rest on the new sofa that he got from the dumpsite just the other day.But unexpectedly something magical happened to him.A stone inlaid on the sofa suddenly brought him to an alternate dimension!And there, Alex rise started, controlling the luck of the world.Everything runs through his favor.Whenever a problem comes up, it gets solve unknowingly.When he lacks money, gold suddenly fell down from the sky.Opening a treasure chest will always give great rewards.Lottery is nonsense, he will win no matter what.When a strong monster is about to kill him, it will trip on a rock and have its head explode, dying by itself.That's how against the sky he is!From then on, Alex became known as 'Fortune', the one who controls luck!

Eren Idril died as an old, decrepit, and piss-poor adventurer by the maws of a D-Rank monster. He had a lot of unfulfilled dreams and desires that couldn't see the light of the day after the light in his own eyes died down.

But fortunately for him and unfortunately for the world, that wasn't his end. Eren was somehow dived back in time when he was a mere teen, attending Lionheart Academy for adventurers.

When life gives him a second chance, Eren decides to exploit it to its fullest. Experience his vile deeds as he partakes in them without feeling the slightest bit of hesitation.