Darkman, also known as Daaku, ascends as the primary antagonist in the second season. Born from the darkness within human hearts, he embodies accumulated negative emotions and hatred. His core drive is resurrection and spreading corruption by manipulating human emotions to amplify darkness.

Targeting Saori Eguchi, a transfer student and professional flute player, Darkman possesses her. He harnesses her musical talents to wield a magical flute that controls and amplifies negative emotions in others. Through Saori, he influences individuals such as Akumi and the Warumo Gang, transforming them into instruments for his schemes. To deepen Saori's vulnerability and secure her cooperation for a large-scale concert designed to spread his influence, Darkman adopts the disguise of Takumi Kiryuu, her former music teacher.

To counter his escalating threat, the fairies develop "sesion magic," combined magical techniques. Darkman is initially defeated by "Golden Mirmo," a form achieved through three-person sesion magic. However, Nezumi (also called Rato) intervenes, resurrecting Darkman and enabling him to continue his campaign against the fairy world. His vendetta intensifies, focusing on destroying the fairy royal lineage, particularly Mirmo's family. This motivation stems from a past romantic rejection that twisted his love into hatred, fueling his vengeance against structures associated with love and happiness.

Darkman's final defeat demands unprecedented coordination: a four-person sesion magic empowers Saori to break free from his control and destroy him. This victory carries a cost, as the clash between dark and magical forces temporarily severs the connection between the human and fairy worlds. The enduring bonds between the main characters and their fairy partners ultimately repair this rift. Following Darkman's destruction, Saori moves to Germany with Akumi as her new fairy partner, ending his direct influence.