『Dian Rubens』

Dian, who first appears in volume three of the novels, is an alchemist. She is in the process of chronicling pagan tales and beliefs so as to print them in books. She carries information about Holo's birthplace Yoitsu. Dian's name sounds very masculine, so she asks Lawrence to call her "Diana".

She is actually an immortal bird deity, similar to how Holo is a wolf deity.