Otherworld Advance Team - Chapter 1733 - 1726: Firepower Superiority System

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.

I dedicated 10 years of my life, focusing solely on regression.[Authority: Death Regression has naturally been nullified.

A young middle school student faces a life-altering choice. Destined for mediocrity and without a War Spiritual Bloodline, he dreams of transcending his ordinary existence and becoming a high-status War Spiritualist. His world is transformed when he becomes bound to the “”Godly Pet Evolution System,”” enabling him to activate his War Spiritual Bloodline and cultivate divine pets, even from the most unlikely sources.Armed with this system, he defies expectations by nurturing underdog spirits into formidable allies. The seemingly weak flower spirit evolves under his care, as does his Lord White Dragon, challenging the mightiest thunder-attribute battle spirits. Even when presented with a Diamond Demonic Spirit Card, he counters with three Epic-Demon Spirit Cards of his own.His journey takes an unexpected turn as powerful entities, including the Six-Tailed Demon Fox, the Phoenix Holy Maiden, and the Queen of the Seas, vie to become his second battle spirit. Faced with a wealth of choices, he refuses to settle for just one and ambitiously aims to harness them all.

When gods gather, lightning will strike and the earth will move. Immortals! Which of the numerous way to immortality should one follow? Immortals are hard to seek, but why should immortals hide? Heaven has no mercy, but humans have emotions, and these emotions hinder the road to longevity!

Train the inner self to stay calm, train the external body to be resistant, then cross the three continents and four seas alone, and fight valiantly with demons and devils! With the heavenly baton in hand, raid the devils and demons without any resistance! Take one step to cross nine stars and chase the sword in the dreams! Traverse a thousand li of river and mountains in a single day! The exceptional beings do not mix with the ordinary! Within the universe, where can one find an obstacle! Moving like a dragon, with talent like a phoenix! The heavenly Daos and stars will guide one’s way!

- Description from Novelupdates