Funeral Parlor Night Watchman, My Client Is a Thousand-Year-Old Fairy

The heroine inherits a dilapidated funeral parlor and is forced to sign a "demon contract", in which she needs to save an ancient demon who is stranded in the world in exchange for life. Each demon soul unlocks a mythical secret history (for example, the legend of the White Snake turns out to be the defection of the medical fairy, and Daji is actually the scapegoat of King Zhou), and is involved in the modern black market of spiritual object trading.