Study Monster Cultivation System - Chapter 353 - 352 Men’s Ideal

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.

“Ding! Choose your idle skill.”“Ding! Idle complete. Language level +999.”“Ding! Choose your idle skill.”“Ding! Idle complete. Basketball level +999.”After a freak accident, Qi Ning acquires the “”Unlimited Idle”” system. But just as the system binds to him, it crashes, leaving a repair time of 999 years. However, to Qi Ning’s surprise, the system still allows him to idle, and with every second of idling, any chosen skill instantly reaches level 999.With his life now dramatically transformed, will Qi Ning’s rise from mediocrity be unstoppable?

Freak Xie Ao Yu originally had no way of cultivating battle qi but, by accident, he got a mysterious godly pellet and he received a supreme emperor blade. That changed his destiny and from then on, he felt the real meaning of life and he made original time and space related battle skills and decisively battled ancient, huge clans and hundreds of continental clans in the Qi Ao continent.

Clouds formed with a flip of a hand and rain formed with another flip. He left the strongest mark in tens of thousands of years of history and created glorious chapters about a tyrant’s anger, blood shed for thousands of miles, the skies hissing from mad blades, and the allegiance acknowledgement of all times.

- Description from Novelupdates

[Additional tag: GL, Yuri, Only Wholesome romance, Harem, Slow romance, Academy, Fluff, Lighthearted, Overpowered Protagonist and Love Interest][Update Daily]Seven Witches. Seven Sins. Mel always found the apocalyptic Gacha World of the 'Witchhunter's Howl' quirky and confusing. The Tragic Witches. The over-powered Saintess. The Bad Ending. And the twelve thousand Dollar she spent on pulling PNG waifus. Really, another salary emptied? Aw, she still hasn’t bought the new, limited merch yet!But now, transmigrated back to the world 15 years before the apocalypse, Mel had a new mission: as the Witch of Lust, she had to seduce the six other witches, plus the Saintess, to prevent the end of everything.Now if only the Kingdom would stop mistaking her for a terrorist, her childhood friend-turned-lover Envy would chill on the yandere vibes, and the Saintess wouldn’t tease her every chance she got...“Ah... I want Miss Pride to be my chair at my tea party...” Mel sighed, just another normal thought on another not-so-normal day.