Mucardia, alias Kyousuke Momoi, serves as a central antagonist who masks his sinister ambitions behind a polished, gentlemanly persona to infiltrate his targets. A humanoid centipede affiliated with the organization Eternal, he schemes to claim the Rose Pact and dominate the Cure Rose Garden. His human guise—marked by long pale blonde hair, grayish skin, pink eyes, and a flamboyant magenta suit paired with an orange shirt—contrasts starkly with his true combat form: pink-skinned, green-eyed, and clad in a red bodysuit adorned with retractable blue spikes and a crimson antenna.

A master manipulator, Mucardia cloaks his cunning in calm charm, exploiting his charisma to manipulate allies and enemies alike, particularly targeting Rin Natsuki. His calculated demeanor fractures into erratic aggression when thwarted, revealing a volatile core. Armed with magic enabling object conjuration, levitation, and size-altering abilities, he challenges adversaries through rigged games and traps, such as shrinking opponents to insect size or luring them into a deceptive magic studio. Though resilient enough to endure assaults like the Rainbow Rose Explosion, his overconfidence leads to defeats, including a pivotal coin-toss loss against Karen Minazuki.

Driven by rivalry with Eternal comrade Anacondy, Mucardia maneuvers to usurp her rank, manipulating allies like Syrup for intelligence—a gambit that ultimately backfires, culminating in his execution by Eternal’s leader after delivering Flora’s letter. Posthumously resurrected in *Pretty Cure All Stars DX 2*, he allies with revived villains to pursue the Rainbow Jewel, underscoring his enduring threat. Notable as Eternal’s sole member with multiple aliases—including the showman “Mr. Magic”—his design weaves entomological motifs into every detail, from spiked armor to centipede-inspired agility, embodying both elegance and grotesque menace.