Rebirth: Splendid Marriage in the 80s - Chapter 83: Huge Harvest

Struck down amid the battle, the Hero and Demon King meet their demise. As their souls linger on the edge of the afterlife, a mysterious force intervenes, merging their fragmented souls together with a new being. Rusty, the living armor, now affected by their memories and presence, embarks on his own quest. Will he seek revenge on those who betrayed the hero, or will he fulfill the desires of the fallen demon king? or instead, forge his own path?

The Fourth Shinobi World War is over. All enemies are defeated. Finally, a long peace reigned in all countries. The Seventh Hokage laid down his arms and lost all his Youth Power. One dream, the goal for which he spent his whole life, has been achieved. His path is over. Is this really the end? Could it end so easily? What if the Savior of this World turns into an arrogant and cunning ruler?Perhaps no one would ever have been able to predict such a result. On that day, everything changed ... Countries, riches and power, the most beautiful women and their young daughters - he will subdue them all! The Seventh Hokage with the strength capable of conquering the heavens chose a different path, now he will take everything for himself and pave the way to absolute world domination!

This is a very interesting thing. It is obviously dim and black, but it can emit a golden light, which makes people deeply fascinated by it…

- Description from novelbuddy

This world has Fox Fairies, River Gods, Water Monsters, Great Demons and Cultivators who seek immortality.