The Stranger I Married - Chapter 6: Debts

In the winter of Taikang Year 3, a girl pays a visit to her future in-laws, the Ning Family of Beiliu, Yangcheng.

After her engagement was denied, the girl decided to hang herself in front of the Ning Family to show them her sincerity.

When the girl who had died opened her eyes once more, many people’s fates were changed forever.

- Description from Novelupdates

Lucifer travels to the world of One Piece, binds the system, and obtains the fruit of words and the power of hell demons at the beginning.Everything Lucifer says will become reality, and matter can be summoned or generated through sound.Flash, lightning, fire, ice, magma, gravity, earthquake, all powerful abilities, Lucifer can use.By beheading enemies, Lucifer earns kill points, which buy more powerful powers.Akainu: As soon as Lucifer speaks, my magma can only be used to light candles.Kizaru: As soon as Lucifer opened his mouth, my flash was slower than a turtle.Whitebeard: My Shock Fruit can't shake a rock.Kaido: My immortality has failed.Redhead: Why is my strongest Conqueror's Haki gone?Five Elders: Please, stop talking.Lucifer: I haven't done it yet, why are you so stupid?Everyone: You didn't do anything, but you did.Lucifer: A gentleman uses his mouth but not his hands.From then on, a hell demon who used his mouth to attack invincible opponents all over the world was born.Disclaimer: This is Translation

The formless ancient world was infested with despicable demons. They hunted and feasted on mankind, keeping the human civilization constantly in a weak and suppressed state.