A Demon's Journey - Chapter 124 - Edwin’s Truth

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.

Climb the Tower.The path to power is ever growing, immeasurable. A peak above a peak, above a peak. There is always the next peak to look up to. A place where dragons eat dragons.In this world where a catastrophe known as “Global Awakening” gave humans different magical abilities to fight the dungeon and monsters that invade earth, Jael is among the weakest—one of the Half Awakened, struggling to survive through odd and humiliating jobs.However his dream of climbing the Dungeon Tower won't be forever buried because a WILL has been left behind. An intent put into a spellbook that's been waiting for just who to claim it.In this golden era of worlds, all eyes are on the Dungeon Tower, where everyone seeks to become its master. “What do you desire? Money and wealth? Honor and pride? Authority and power? Revenge? Do you want to reverse your failures? Or something beyond them all? Whatever you desire—it is here. If only you climb.”Follow Jael’s journey as he ascends the Dungeon Tower, determined to create a new legend for himself.

"In her previous life, she is used by her first love to send her own company into the tiger's den. She becomes bankrupt, gets kicked out of the house by her father, and becomes the target of ridicule by the family. Worst of all, she believes her best friend's lies, thinking that everything was done by her ‘husband’. Under her best friend's ploys, she almost kills him and is ultimately sentenced to prison, where she dies of depression.

To Producers, the two of them couldn’t be more drastically different voice actors.