Divine Beast Ascension - Chapter 616 - Scramble to Safety

Protagonist travels between different anime worlds to right wrongs and uncover his reason for being along the way.

- Description from Novelupdates

Nile Santos lived a life of sacrifice — always stepping aside, always giving others the best gear, always following orders without question. In the end, none of it mattered. His comrades fell, his body was broken, and he died a meaningless death in the final battle against an unstoppable force.But fate isn’t finished with him.Offered a second chance by the very beings who led him to ruin, he’s thrust back in time with all his memories intact. This time, though, he’s not playing the role of a noble shield. No more selflessness. No more obedience. No more being a pawn.Armed with future knowledge and a will forged in failure, he vows to rewrite his story — to take everything for himself. Skills, loot, allies, power… all of it. It’s time for one man to climb to the top, no matter what it takes.Author's other storiesThe Unrivaled Holder: Rise of the Dragon Monarch - 3rd Season OngoingI Ascend Alone - Ongoing

Ten years ago, Magnolia was blamed for her sister’s death and cast out of her pack. Her Alpha father’s final words “Why did she die, but not you?” drove her into exile. She lived among humans, hiding her identity, her wolf, and her pain.Now, at twenty-eight, Magnolia learns her mate is none other than Rhett Callahan , the powerful Alpha of the strongest pack and heir to a billion-dollar empire. But instead of love, he offers her a contract: marry him for one year so he can fulfill the requirements of his inheritance.Magnolia accepts to save her parents’ home but finds herself in a loveless arrangement, mocked by the pack and haunted by the past. Then Camille returns with another woman, the one he truly loves… and it’s Magnolia ’s sister, long thought dead.As secrets explode and bonds unravel, Magnolia must decide if she can forgive the mate who rejected her or burn the past down with him in it.

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.