 On their journey, they are joined by the sage Zhuzhen Liu, an expert in the magic of Yin and yang; Margarete Gertrude Zelle, an infamous spy and bomb expert; Keith Valentine, a centuries-old vampire who isolates himself from the outside world; and Halley Brancket, a street urchin and gang leader from London who possesses powerful magical abilities.The main antagonist is initially introduced as "Roger Bacon"; his true identity is Albert Simon, a former Cardinal who achieved immortality and wields dark powers.The secondary antagonist is Dehuai, a powerful sorcerer obsessed with obtaining power over a dark god.