Naegwani Doen Namja

Mansuk, a low-born slave, was abandoned in the mountains right after birth, supposedly for stealing the energy of the Samsin Halmae (goddess of childbirth). Fortunately, he was picked up by a peddler and wandered through the eight provinces of Joseon. Thanks to his natural eloquence and quick wit, Mansuk achieved great success as both a righteous hero and a swindler. Believing that 'a swindler starves if he becomes famous,' he prepares for his last big score. His final goal is to steal the blue and white porcelain belonging to Lord Park, Hanyang's wealthiest man. However, he fails and is caught. Under Lord Park's command, he becomes a 'fake eunuch' and infiltrates the palace – as the exclusive eunuch for Queen Gyeongye, who is said to be even scarier than the King!

(Source: Lezhin, translated)