Regina, born from the fractured darkness of Princess Marie Angelica’s heart after the princess split her soul to shield her kingdom, serves as King Mercenare’s daughter and second-in-command. With long blonde hair tied by a red bow, a dark grey dress edged in red, and piercing blue eyes that crimson under brainwashing, her appearance shifts when corrupted: her skin whitens, her hair darkens, and her red accents deepen to violet. A manipulative, vain antagonist, she commands through threats and flattery, dominating subordinates like the Selfish Trio and resenting rivals she deems prettier. Her playful irresponsibility lures others, especially Maya, into neglecting duties for games, though early interactions with Maya stir unexpected curiosity about true friendship.

Regina’s journey pivots when bonding with Maya softens her edges, exposing vulnerability. Stealing a red crystal from Marie Angelica’s statue triggers aggressive brainwashing, yet Maya’s unwavering compassion sparks doubt in Regina’s loyalties. This culminates in her sacrificing herself to save Maya from lava, a selfless act that shatters Mercenare’s control and briefly allies her with the Glitter Force. Despite this defiance, conflicted affection for her father lingers. Recaptured and re-brainwashed, she attacks the Glitter Force with heightened powers until Glitter Ace disrupts her conditioning, enabling her rescue.

Her arc intertwines with Natalie, as both embody divided halves of Marie Angelica’s heart. Regina’s love—for Mercenare and her newfound friends—ultimately purges his corruption. Beyond the main narrative, a novel reveals her fusion with allies as Cure Joker, an eccentric warrior with amplified combat skills. Post-battle, she joins the protagonists’ school, navigating ordinary life beside them without formal Glitter Force membership. Her powers include manifesting monsters from others’ hidden selfishness and wielding the Miracle Dragon Glaive, a weapon fueled by her latent capacity for love.