For a wizard, blood has a myriad of uses, with different bloods serving different purposes.
The blood of magical plants, which is scant and primarily used in magic potions, is relatively singular in its usage. For instance, the Kirin Blood Exhaustion of the palm family can be used to activate blood circulation, relieve pain, heal wounds, and regenerate flesh; the blood of Alder smeared on animals can tame them; the root blood of Mandala Grass, aged over a hundred years, can be used to cure deafness.
The application of magical creatures' blood is relatively broader. For example, the aortic blood of the Tanggula Ice Chilong can be used to extract Mithril; the heart's blood of the Changbai Mountain's Chi Qiu can act as a catalyst in many magical experiments; the ink made from the blood of East Sea Shenlong is a high-end item for transcribing illusion spells; even the blood of seemingly useless Kappa in the eyes of many wizards can be used to feed the offspring of Fish Wives.