TV-Series
Description
Diana, also known as the Queen, is a major antagonist from the anime and manga series MÄR. She holds the title of Queen within the Chess Pieces, making her the second most powerful member of that organization, and is a former queen of the Kingdom of Lestava. Her actions serve as the catalyst for the main events of the story.

Standing 173 centimeters tall, Diana is a striking figure with long pink hair and red eyes. Her appearance varies between the manga and anime adaptations; in the manga, she wears a revealing black gown with a metal belt and chains, while her anime design is more modest with simpler dress textures. She is consistently depicted wearing a black mask covering the lower part of her face, gauntlets, bracelets, a choker, and elaborate necklaces.

Diana is introduced as a sinister and selfish individual, preferring to operate from the shadows and manipulate others to do her bidding without direct involvement. She is a master strategist who has orchestrated much of the conflict in MÄR-Heaven, using the Chess Pieces and the Knights as her weapons for conquest. Despite her cold exterior and ambition, her true personality has been heavily clouded and manipulated by the King. Her original self was that of a caring and well-liked citizen, particularly towards her younger sister, Dorothy. This hidden loving nature is only restored to her at the moment of her death, suggesting the King's influence has suppressed her genuine character.

Diana's motivations are driven by an immense craving for power that began a decade before the series' main timeline. Abandoning her loyalty to her homeland of Caldia, she released the knight Phantom from imprisonment, and together they stole hundreds of magical ÄRMs, including the living weapon Babbo. Her ultimate goal extended beyond conquering MÄR-Heaven; she aimed to dominate Ginta Toramizu's world, believing she could use its advanced technology to easily subjugate the people of her own dimension. To achieve this, she used a unique ÄRM to exploit the connection between her stepdaughter Snow and Ginta's friend Koyuki, creating a portal between the two worlds.

Diana's key relationships define much of her story arc. She is the older sister of Dorothy, a member of Team MÄR, and a powerful witch in her own right. Before her corruption, she was a dedicated sister who trained Dorothy and made dolls for her. This past creates a deep and tragic conflict between them. Diana also became the stepmother to Snow, and for a time, the two had a genuine, loving relationship as mother and daughter. However, her ambition eventually led her to use Snow as a pawn in her larger scheme. The King, her superior in the Chess Pieces, is the one who manipulated her and clouded her true self, making her a tool for his own plans.

Over the course of the story, Diana remains in the background, observing the War Games through a crystal ball and giving orders to her subordinates like Phantom and Peta. She is seen as the key figure who shaped MÄR-Heaven into a land of war and destruction. Her development culminates in her final confrontation with her sister, Dorothy. In their evenly matched battle, where they counter each other's Guardian ÄRMs, Diana receives a fatal wound. As she dies in Dorothy's arms, the corrupting influence of the King fades, and she returns to her true self as a loving sister, apologizing to Dorothy for her actions.

As the Queen of the Chess Pieces, Diana is considered one of the strongest characters in the series and the most powerful witch in MÄR-Heaven. She possesses a wide arsenal of ÄRMs, magical artifacts that grant special abilities. Her primary weapon is the Aeros Staff, a scepter that symbolizes her supremacy and allows her to master the wind, similar to her sister's Zephyrus Broom. For transformation, she uses a belt Ghost ÄRM called Dalia, which fuses her body with wings and claws like a harpy. She also commands a choker Guardian ÄRM named Cerberus, which summons a three-headed, netherworld monster. Her other Guardians include a giant octopus, and Pinocchio II, a remade version of the puppet Knight she once created for her sister. Diana's offensive capabilities include a nature ÄRM called the Ring of Ends, which creates a poisonous mist wheel in the manga, and in the anime, she uses a purple slime to transform others into monsters. She also possesses a darkness ÄRM, the Death Cube, which traps victims inside a deadly puzzle. To connect the two worlds, she uses a unique ÄRM, referred to as the World Tunneler, which takes the form of a large bubble that opens a portal.