https://www.novelupdates.com/series/apocalypse-arrival/

Description [Edit]

This is a story in which the big devil accidentally becomes a poor little loyal dog.

When Chu Qianxun was reborn and returned to the beginning of the apocalypse, she vowed to live a better life, live longer, and stay away from those dangerous people and things. One day, she accidentally rescued an immortal man. After washing his face clean, Chu Qianxun found out in horror that this man was a notorious, cold-blooded and ruthless great demon who made all mankind fearful in the late apocalypse. Whenever Chu Qianxun thought about getting rid of this big demon quietly, that person would always grab the corner of her clothes and say pitifully, 'You, do you want to abandon me again?'

The dream the FL had and woke up from in 'Let the villian go' is this novel.