Ooh, I Smell Jealousy

The Crown Princess of a beast kingdom ruled by women spent her life chasing four cold men she idolised, and to please them she pushed her own fiancé until he turned into a beast and lost his mind. When he came for her, none of the four moved to help, and she died in his hands. Nina Vale, who in her own world kept a string of men on the line at all times, wakes up in that princess's body with the whole court treating her as a disgrace. A voice in her head announces a system that levels her up each time she makes a man jealous. Nina falls back on what she already knows about keeping several men waiting at once. She stops fawning on the four, turns her attention to other men in the palace, and lets them watch her do it. The four, who had grown used to having her at their feet, find they cannot stand it and start competing for her. As her level climbs the system hands her new abilities, among them a look that stops whoever meets her eyes and a face that reshapes itself into whatever the man in front of her finds most attractive. By then most of the men in the palace are jealous of one another over her.