TV-Series
Description
Mephisto, once king of Major Land, was husband to Queen Aphrodite and father of Ako Shirabe, later revealed as Cure Muse. Before the series began, he ventured into the Forest of Evil Echoes seeking the stolen Healing Chest. Ambushed by Noise's minion Golem, he succumbed to infection by "evil Noise," which brainwashed him and sealed most memories, leaving only hazy recollections of the forest. Believing his implanted ambition to spread sadness was his true will, he established Minor Land as its ruler.

Brainwashed as Minor Land's king, Mephisto sported long pink hair, a beard, tired eyes with dark circles, and a vibrant Arabian-inspired costume: a red cloak, bird bone-shaped shoulder pads, and a treble clef ornament on his forehead. His personality shifted to a comedically inept, emotionally childish antagonist, more akin to a schoolyard bully than a menacing villain. He outright rejected love and friendship, readily abandoned subordinates, and obsessively pursued replacing the "Melody of Happiness" with the "Melody of Sorrow" to drown all worlds in sadness, primarily serving as comic relief.

His abilities included crafting Negatones—corrupted musical notes fused with objects—as seen when transforming Kanon Town's Clock Tower. He generated soldiers from his hair and used the "evil Noise" to control others, while remaining under Noise's thrall. During a monstrous Negatone transformation (triggered by intensified brainwashing), he gained immense strength, shattered barriers like the Beat Barrier, fired destructive energy blasts, and summoned twin-headed skeletal dragons from his back that emitted devastating beams.

His reign involved attacking Major Land during its annual ceremony, corrupting the Melody of Happiness with aid from his brainwashed ally Siren. After Queen Aphrodite scattered the Legendary Score's notes to Earth, he dispatched Siren and the Trio the Minor to retrieve them while researching the Pretty Cure warriors. He identified their reliance on "harmony power" and communicated with minions through water or mirror portals.

Redemption sparked upon discovering Cure Muse was his daughter Ako. Noise intensified control, turning him monstrous, but Ako's heartfelt plea in battle shattered the brainwashing. Freed from the "evil Noise," he reverted to his original personality: a clumsy yet loving husband and father who doted on Ako and expressed deep guilt for corrupting Siren and the Trio the Minor. His appearance shifted to regal attire: white shirt, purple trousers, light red-and-purple vest with a gold belt, and red cape.

Post-purification, he regained his "Holy Thunder" ability, a light-based beam, using it to purify Bassdrum and Baritone before collapsing unconscious. Later petrified by Noise, he was restored by Hummy's song. As Major Land's restored king, he apologized to the Pretty Cure team, vowed never to sadden Ako again, and entrusted her to their care, maintaining informal relationships with the heroes despite his royal status.