One of the most potent curing serum's, the Fiif'no serum is a medical serum produced by the Sangerye family from the root of the Fiif'no plant. The serum allows them to cure Jinoo and return them back to their human form.
Often crafted by the women of the Sangerye family, the serum is a green substance that is injected into infected Jinoo. This renders them incapacitated and slowly transforms them into their human variants.