The Demon's Menu - Chapter 125: As You Expected (Five more updates for subscription~ asking for monthly passes~)

Xiaya reincarnated in the Dragon Ball Universe as a Saiyan 12 years before the destruction of Planet Vegeta.

Watch him as he creates the strongest legend of Dragon Ball World from the beginning.

- Description from Novelupdates

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.

In the year 2544, magic and technology are an everyday thing. Humans now have wonderous abilities that transcend the physical laws of the world.Eighteen-year-old Gavin has always been an ordinary human—until a shocking truth shatters his reality. He was found as a baby, the sole survivor of a massacre that wiped out his birth clan. His entire life has been a lie. He’s not human—he’s a werewolf, one of the last of the alpha predators the world sought to destroy.Determined to understand his true nature and protect the one person he’s always loved—Erza O'Malley, his best friend and the woman who has always been his home—Gavin enrolls in a magical academy. But learning to shift is only the beginning. As hidden forces stir and the ghosts of the past resurface, Gavin must decide: will he remain in the shadows, or will he embrace the predator within to fight for a future that was never meant to be his?Perfect for fans of action-packed paranormal fantasy, forbidden love, and a world where magic and science collide.

Mu Yue traveled to the world of Naruto and became an ordinary chuunin teacher at Konoha Ninja School and a member of the Root Organization.

Fortunately, after awakening the teacher system, you can become stronger by teaching.

In order not to become Danzo’s consumables, Mu Yue worked hard to teach and increase her strength.

“Complete the teaching rated A for the first time and receive the reward – mastery of fire attribute chakra properties change.”

“Under your guidance, Uchiha Shisui has worked hard to practice, and his overall strength has been greatly improved, and he has been rewarded – the Immortal Human Body!”

Under Mu Yue’s guidance, Zhishui understood that the village’s enemies were not necessarily other big countries, but could also be within the village. People who spoke righteously about the will of fire might not necessarily act in accordance with the will of fire.

Obito got rid of the title of being the weakest person in the ninja school, and Metkai became a master of physical skills even earlier…

- Description from novelbuddy