Ashen God - Chapter 669 - 668: Shield Value Limit Increase

Kurokawa Risa is an ordinary office worker, who has practiced lots of cooking while living alone. One day, she wakes up in another world, with a concerned little spirit hovering over her! She has apparently been transported to a magical, spirit-filled realm by the will of the goddess, and there is no known way for her to go back. She is taken in by a wealthy couple, and they and her new spirit helper treat her with nothing but kindness. There is one problem, however–the food in this magical world is gross! Risa insists on helping the household cooking staff prepare a traditional meal from her world, and it is a big hit with her hosts. Soon Risa knows what she should do in this new world; she should open a cafe and treat everyone to delicious food!

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.

Tachikawa Shin always thought he was a decent, upright man—unfortunately, he’d been saddled with an indecent favorability system.Raise others’ affection to grow stronger?“I’d rather stay away from these witches, but this concerns my safety and physical integrity... Well, it seems I don’t have a choice,” Tachikawa Shin said righteously, with absolutely no perversion whatsoever.All hail the Rizzler!

Amakawa Haruto died before he’d the chance to reunite with his childhood friend who disappeared five years ago. Rio, a young boy living in the slums seeks revenge for his mother who was murdered in cold blood in front of him when he was only five years of age.

There exists the earth many knows of and there exists an alternate world. Two people, each with their own backgrounds and values. For odd reasons, the memories and personality of Haruto, one who should have died resurrects in Rio’s body. As the two are confused over their memories and personality fusing together, Rio (Haruto) decides to live in this new world.

Along with Haruto’s memories, Rio awakens an unknown but special power. If he’s to use it, it looks as if he can live a better life, but before that, Rio encountered a kidnapping which results in involving the two princesses of the Bertam Kingdom.

After saving the princesses, Rio is given a scholarship to attend the Royal Academy, a school for the rich and powerful. His background being a poor orphan who once lived in the slums, the school full of nobles was rather a detestable place to stay at.