The supporting character's harem is very normal - Chapter 37 Miam!

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.

[Mature Content] Divorced and in debt, Elena decides to become the contract wife of three rich and famous men. A fair exchange begins between a woman disillusioned about love and men with their own demands and desires. But when they demand for more than her body, she discovers many dark truths as the past slowly catches up to her.

A world where all of the greatest in all dimensions have gathered.

Three out of five were the strongest in their world, and one of them was considered the strongest in history.

A crazy world where a wandering goblin would be above level 90.

Asgard, otherwise known as “Heaven above the heavens.”

In a world where all of the monsters of the worlds meet, Vulcan’s new adventure begins.

“Married rich for three years with no child born. Just when she was finally cured of infertility and ready to give him a child, he brought home his pregnant mistress in high profile.