I Became the Tyrant’s Servant [MagusManga]
A former call center employee finds herself transported into a fantasy novel, where she becomes the "servant" of the male protagonist, a cruel tyrant who kills anyone he doesn't like and lives in lust.
She doesn't want to die like the original character, so she plans to escape before the tyrant finds the female protagonist, who is the only one capable of changing his heart. To do this, she begins to do business, buy ships and train concubines for the tyrant. However, her plans are thwarted when the tyrant begins to take an interest in her and pursues her relentlessly.
Will she be able to escape her fate or will she fall in love with the man she was supposed to hate?