It is recorded in the Compendium of Materia Medica that there is a thing in the world called Oak Horn Gall. Its shape is specific, born on an oak tree, with a horn-like shape, hard texture, and mottled skin.

Oak Horn Gall is extremely rare and needs to be found at a specific time and on a specific oak tree. Its effect is quite strange. It can be used as medicine in the medical system and has a wonderful effect on certain diseases. In case of physical discomfort, experienced doctors often use Oak Horn Gall in combination with other herbs. After decoction, it may relieve the pain.

In the eyes of the Fang family, Oak Horn Gall can not only heal people's pain, but also has unique uses in the art of alchemy and pharmacy. It may be able to reconcile medicinal properties and make the effect of medicinal pills more superior, so it is regarded as a treasure by many Fang families. When refining high-quality medicinal pills, they will often look for Oak Horn Gall to join them in order to achieve extraordinary effects.