This medicine was needed by Long Siye to heal the strange sickness of Di Fuyi, so Gu Xijiu was very focused on refining it. She had not left the room for the entire day. She even needed Di Fuyi to send her meals to her personally. They had separated and are currently staying in two different guestrooms as they did not want to be suspected by Long Siye.
Gu Xijiu's skill of refining medicine was taught to her by the Firmament Stone. She also had some knowledge of modern-day medicine. Although Di Fuyi was also a master in refining medicine, he did not know anything about modern-day medicines which gave Gu Xijiu an advantage. Besides, he was currently hiding his true identity so he could not reveal his high-end skills of refining medicine. Therefore, the job of refining the medicine was assigned to Gu Xijiu.