The Female Demon Lord Cuddles and Coos in My Arms Every Night

(One heroine, daily-life sweetness, plenty of romance, a cultivation system, an expansive setting) Zhou Jin transmigrates into a romance novel and discovers he's the foolish cannon fodder who gives someone else the wedding dress: he hands over his family's military power in exchange for a grand wedding to his goddess! But he dies a miserable death on the wedding day, and the Zhou family is wiped out. Following the System's instructions, Zhou Jin transforms into a judge of true love and throws in his lot with the villainess, who will turn evil later in the story. He'll use love to melt the heart of the aloof empress! But something... doesn't seem right. The empress, who should have been cold and distant, is getting clingier and more adorably airheaded by the day? My Lady Villain! Your character is falling apart!