MTL - Becoming Stronger Through Touching Treasures, not Women! - Chapter 224 reservoir?

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.

After 2000 years has passed, the ruthless demon lord has just been reincarnated! But his aptitude at an academy for nurturing candidates for demon lords is, “Inept”!?

Having the capability to destroy humans, elementals, and gods, after a long period of countless wars and strife, Arnos the demon lord became sick and tired of all that and longed for a peaceful world, so he decided to reincarnate to the future.

However, what awaited him after his reincarnation is a world too used to peace that his descendants became too weak due to a huge weakening in magical powers.

Arnos enrolled in the Maou Academy established to find any students that might be the demon lord’s reincarnation, but his powers are too extraordinary that those in the academy couldn’t properly judge his powers, so he’s regarded as an “Inept student”. Being underestimated and avoided by most people there, he recruited a girl friendly to him, Misha, as his subordinate and comrade, and strives to climb to the top of the demon race hierarchy to one day reclaim his former title and status.

In her previous life, she loved a prince who didn’t love her back. She was framed and her heart was torn out. After rebirth, she wanted to live unrestrainedly, but accidentally married Ling Chen, the Fourth Prince who was calculating, manipulative, and had bad reputation.

Conspiracy, hypocrisy, greed, framing, blackmail, she took them all one by one. Getting a big payoff for a small effort, love is like a sharp knife!

Lan Ling: Why did Wangye climb over the wall and come to my room?
Ling Chen: Why do you think I’m here?
Lan Ling: Does Wangye likes climbing to someone else’s bed in the middle of the night?
Ling Chen: Presumptuous! How is this someone else’s bed?

- Description from Novelupdates