Naruto: Reborn as Neji Hyuga After Dying in One Piece - Chapter 81. Whoever Marries Her, I Pity Him

The first great emperor in the world was betrayed by his confidante and perished. Millions of years later, the great emperor’s soul returned and was reborn as Ye Yan, the son-in-law who was kicked out by the Chu family with a letter of divorce, restarting the supreme journey. Open the gate of immortality, kill the Jiuzhongtian, and cast an invincible name again!

- Description from novelbuddy

mc gets transmigrated to Fallout New Vegas with the merchant system. let the questionable adventure begin.

Ryan «Quicksave» Romano is an eccentric adventurer with a strange power: he can create a save-point in time and redo his life whenever he dies. Arriving in New Rome, the glitzy capital of sin of a rebuilding Europe, he finds the city torn between mega-corporations, sponsored heroes, superpowered criminals, and true monsters. It’s a time of chaos, where potions can grant the power to rule the world and dangers lurk everywhere.