Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 15 - 15-37. Divine Punishment (6), Hero Meiko

She fought in the Battle of Changping and witnessed the killing of hundreds of thousands. She once led the Qin Iron Calvary and battled against the Six Kingdoms. She has seen a third of the land and witnessed the breaking of mountains and rivers. The sound of a grand zither and the light of a great female emperor. A prosperous world that was forged on the battlefield. Yet, these two thousand years are forgotten from history.

- Description from Novelupdates

A million years ago, he had traversed the Nine Heavens and Ten Earths, braving countless mysterious Life Prohibition Zones, in search of a way to resurrect that foolish woman, but inadvertently learned one earth-shattering secret after another. Thereafter, he went through nine cycles of reincarnation, strategizing over the world, casting his net across the heavens, with the Myriad Realms as his board! In this life, he had returned from reincarnation, his Qi engulfing mountains and rivers, “It’s time to close the net...”

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

“Shameless Xia Ping, not only did you steal my martial arts manual and medicinal pills, you even took my fiancée! We’re not finished!”