My Mother is a Gendersmith

Lily's mother uses eel wine to help people change their fetus's gender. After the wine causes an accident, the town is retaliated by eels. Lily uncovers her mother's secret and learns she's the reincarnation of the Eel Immortal. The mayor tries to eat her flesh for divine power, only to reap what he sows. Lily returns to the mountains to be the Eel Immortal again.