Forbidden Cravings - Chapter 4: Giving her Head (R-18)

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.

Living an unfulfilled life, Zack Gray meets an untimely end–that is, until he’s given a second chance, in a new world, under a new name: “Leon Schoeller.” Heir to the Schoeller Estate, a powerful and prestigious noble family, a life of luxury surrounded by maids and butlers of elite skills of their own awaits the reborn man.[Lord System Activated.]In addition to being blessed with a genius mind and magical talent, the [Lord System] grants Leon supernatural abilities, from empowering his servants, conquering beasts, and even manipulating his mansion.However, as gifted as he finds himself, the world around him is full of lurking threats, forcing him to level up if he expects to keep his cozy life intact.

He was once Head of the Immortal Sects.

Jiang Zheliu resisted the world’s destruction, protecting the people single-handedly. After losing all his spiritual energy, his hair turned white overnight.

All that remained was a millennium passed in vain, and a grave disease.

He distanced himself from the Cultivation World, went to Zhongnan Mountain to collect herbal medicines and grow flowers, as if to retire.

Until….. Those little demons he had once saved, his cherished juniors, even those devils that he had suppressed innumerable times, all came knocking at his door, each more excited than the next gripping his hand:

“Qianbei, what type do you like? Can you not be so rigid on your requirements?”

Jiang Zheliu: “……？？？”

Wenren Ye is newly appointed Devil Lord of the Devil Realm.

He is cold-hearted, devilishly handsome, and when he was younger he suffered a humiliating defeat at the hands of a certain Head of the Immortal Sects.

Still obsessed with this defeat, Wenren Ye hurried through the night to Zhongnan Mountain, but all he saw was white-haired weak Immortal Sects Leader, with droopy eyes, sick to the bone, with freshly coughed up blood staining his lips.

His obsession was still alive, but his heart was also thumping.

- Description from Novelupdates

An avid Xianxia reader suddenly has his dream come true—he wakes up in a world of cultivation. The only problem? Maybe it wasn’t really his dream after all.Now, faced with the daunting reality of countless cultivation realms to climb, countless worlds to ascend through, and countless arrogant young masters to deal with, despair begins to settle in.Fortunately, a glimmer of hope appears amidst the chaos: a mysterious system that could change everything.Armed with elders, ancestors, and a sect leader—who are all actually his own avatars—he no longer feels completely overwhelmed.“At least I don’t have to do it all alone… well, technically, I do. They’re just avatars, after all.”