Transmigrated As A Villain, The Heroines Are Also Regressors? - Chapter 86: Is The Gu Family Stupid?

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.

Side story of Kyoukai Senjou no Horizon bundled with the first press release of the 1st, 3rd, 5th and 7th Blu-ray volumes of both seasons of anime.

This side story follows Asama, Kimi and Mitotsudaira aboard Musashi one year before the beginning of the main story, as Asama is considering to create a music band together with her two friends for the next festival in Aki, a territory under the governance of K.P.A. Italia.

The chief female forensic investigator, Ran Yan was secretly killed by her assistant. Unexpectedly, she was reborn in the years of the Tang dynasty. After experiencing a narrow escape, she fled from Jiangnan to Chang’an. Although, Chang’an was at the beginning of its flourishing period under the Li family’s Tang dynasty, various princes were vying for the throne by using all kinds of strategies. This was the dark days of the imperial court, where one needed to walk on a tightrope as one’s life was as powerless as an ant. The Xiao family controlled a large amount of wealth so inevitably they also became involved in the conflicts.

After arriving in Chang’an, she discovered many suspicious incidents: the original owner had unexplainable amnesia but his family was indifferent. She once again saw the orchid shaped clay inkstone, a valuable object that her mother has given her in modern times. Hence, could it be that she can time travel back? In order to survive in the Tang dynasty, she displayed her strong spirit and willpower by learning medicine from a doctor, pretended that she benefited from being sick on how to cure diseases, suffered hardship in earning money, manufactured penicillin, cured syphilis, and used her autopsy skill and experience to solve each and every murder mysteries.

- Description from Novelupdates

After being reborn, Bella Green is determined to punish the scum, slap faces, and sing her way to the pinnacle of life. However, she is accidentally picked up by the person she least wants to see and taken home as a cheap 'brother.'Faced with the naughty yet particularly disobedient little Demon King, Mason Bennett sternly instructs: “No fighting, no skipping class, no dating!”One day, the little Demon King shows up on television in a stunning long dress, and Mason Bennett is furious, immediately tying her up and bringing her home for an in-depth lesson!!Looking at her suitors who were beaten up and unable to take care of themselves, Bella's eye twitches, what about the promise of no fighting?Being forcibly dragged out of the classroom and carried home by a certain jealous king while attending class, what about the promise of no skipping classes?Finally coaxed and deceived into the civil affairs bureau, Bella teared up, damn it, what about the promise of no dating!!!