MTL - True Marvel World - Chapter 425 The future of the earth is up to me

Xue Xi is forced to fall in love at first sight with this dangerous man on their first meeting. With death being the only other option, she makes the first move:

She was the Empire’s top-tier elite agent, skilled in both medicine and poison. One day, she transmigrated into the body of a foolish, mentally disabled, and hideously ugly waste. But when her soul entered, the Phoenix Maiden returned, shaking the heavens and the earth! Those who wronged her will be repaid a hundredfold. Those who insulted her will pay back a thousandfold. Call her useless? Wait and see what true genius in cultivation looks like. Call her a fool? Wait and see who the top-tier alchemist really is. Say no one wants her? Watch as the strongest man follows her everywhere. From now on, divine beasts and handsome men will walk by her side, and she’ll roam the heavens and earth as she pleases.‘Qingcheng, from now on, I’ll help you manage the household and raise our children. This world and I will belong to you!’ said the scheming man with a flattering smile.The woman coldly met his gaze and replied, ‘The world and its empire are within my grasp. Now, get lost!’

[The Demon King is Dead], a story in which the Demon King got immediately killed in the Prologue. I became the ‘Demon Prince’ of said novel.

…Help me.