Joker operates as the secondary antagonist, the primary liaison connecting the evil emperor Pierrot to the Bad End Kingdom's three commanders: Wolfrun, Majorina, and Akaoni. His harlequin-inspired appearance features a white half-mask obscuring his eyes, a multicolored jester-hat hairstyle (blue, red, yellow, violet), and a violet-and-white bodysuit with a cape. Intense rage transforms his face into a monstrous visage with red eyes and fangs. Before the main conflict, Joker visited Märchenland and discovered three ostracized fairies resenting their association with villainous fairy tale roles. Exploiting their resentment, he recruited them as commanders to lead the assault on their homeland. Concurrently, he hunted the Miracle Jewel, intending its destruction to eradicate all hope and ensure absolute despair. His core motivation centers on eradicating hope, dreams, and miracles to achieve "true despair," aligning with Pierrot's goal of universal destruction. Strategically manipulative and resourceful, Joker supplies the commanders with specialized Akanbe noses crafted from his headdress baubles to counter the protagonists. Blue noses grant immunity to basic attacks; black noses create Hyper Akanbes, draining the commanders' life force. He wields psychological warfare, trapping characters in the complacent dreamscape of the "Ball of Neglect" and exploiting personal conflicts—like Cure Beauty's struggle between duties and studying abroad—to shatter resolve and harvest negative energy. In combat, Joker wields playing cards as weapons, shields, and teleportation tools. He effortlessly engages all protagonists simultaneously, absorbs Akanbes to augment his strength, and creates illusions via duplication. Following the commanders' repeated failures, he merges their residual darkness with stolen Cure Decors to fabricate "Bad End Pretty Cure" distractions. During the climax, he reveals his true objective is annihilating the Miracle Jewel, not reviving Pierrot. When Pierrot's revival initiates, Joker dissolves into black ink, ecstatically reuniting with his master. A novel epilogue, set ten years post-Pierrot's defeat, confirms Joker's survival. Now an immortal entity of resentment lacking his original form, he possesses Miyuki's picture book, "The Greatest Smile," transforming into the winged, gargantuan book-monster "Bad Joker," spewing evil fog. He corrupts the Mysterious Library, trapping the protagonists in simulations of their future lives to feed on their negativity. Though defeated again, the narrative implies his eventual reconstitution.