MTL - Winner Takes All - Chapter 31

The price for saving the world is the right to rule it. After saving a faraway land, Lyn Rivers was cast back to Earth. Wanting the admiration, prestige, and glory of saving that realm, she forced her way back. But she was forgotten, and someone else claimed credit for her deeds. Now, with the power of a deity of destruction, she desires nothing more than to claim her place in history. To do that she will conquer dungeons, make alliances, destroy kingdoms, and build an empire. After all, why ruin the world when you can bend it to your will?

A man was transported to Ancient China and eventually became a servant of a declining household without a male heir. He utilized his wits and modern knowledge to help the household and eventually become trapped in the sea of political turmoils of the period.

- Description from Novelupdates

…but it seems pretty doable.