MTL - After the Eldest Sister-in-law Died Young, Dai Wen Remarried. - Chapter 545 farewell letter

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.

Takahiro Nao, a 25-year-old burdened by crushing debt and driven solely by his love for his struggling family, meets a tragic end—until a mysterious Goddess of Benevolence offers him a second chance: reincarnated in another world, and his efforts there will provide for his family back on Earth. Awakening in the body of Naoki von Blackmore, a disgraced “Failed Hero,” Nao is thrust into a realm of sword and magic, monsters, and war, tasked with the impossible mission of defeating the Demon King. With newfound powers, a shadowy past, and the weight of two worlds on his shoulders, he must battle not only relentless enemies but fate itself. Blending emotional depth, thrilling action, moments of humor, and a spark of romance, this gripping isekai adventure asks: how far would you go—and what would you sacrifice—for the people you love?

In 2028, the Abyss invaded, accompanied by the arrival of Extraordinary Power, bringing Blue Star into the era of universal awakening.Chu Xiu, a transmigrator who inherits the Infinite Saint Dao Sect, looks at the insane Demonic Secret Techniques before him and falls into contemplation.“Crafting a Bone Banner requires the sacrifice of hundreds of mortals. Well... do zombies count as humans?”And he quickly discovers that those Abyss creatures work exceptionally well for crafting Demonic Artifacts. Most importantly, their number was almost inexhaustible!

Having transmigrated into a little farmer girl, her father passed and her mother turned crazed. Facing a frail household, Qian Yixiu remained calm, her rise relied on strength, and also on the luck she had when being a “ghost”.Together with her younger brother, she strived to build wealth with one hand and protect her beauty with the other...