OVA
Description
Clef, Chief Sorcerer of Cephiro and former personal attendant to Princess Emeraude, appears as a boy of ten or eleven with light purple hair, light blue eyes, and fair skin, though his true age is 745 years, reflecting Cephiro's ability to alter form through willpower. He wears elaborate white robes, a diadem featuring aquamarine gems and a central blue horn, and gold earrings. His primary tool is a tall staff topped with a carved animal figure and two large gemstones, blue and purple; the blue gem glows during spellcasting.

His personality blends wisdom, authority, and calm, occasionally punctuated by temper, such as striking Umi with his staff when mocked for his youthful appearance. He harbors deep guilt for concealing the truth from the Magic Knights about their destined role to kill Princess Emeraude, a secret kept throughout their initial quest. This guilt intensifies later, prompting an open apology. Despite pragmatism, he shows warmth and protectiveness, exemplified by preparing a sleeping potion for an anxious Umi.

Clef tutored prominent figures like Emeraude, Zagato, Lantis, and Alcyone in magic. After Emeraude became the Pillar, he appointed Lantis as her guard captain and Zagato as high priest. When Emeraude decided to summon the Magic Knights to end her life due to forbidden love undermining her role, Clef objected but complied. He prepared for their arrival by enchanting Presea's door to admit only the knights and entrusting her with Mokona.

In the first season, Clef guides the summoned Magic Knights—Hikaru, Umi, and Fuu—providing their initial armor and magic while awakening their latent abilities. After a confrontation with his former student Alcyone, Zagato petrifies him, though he continues advising the knights via Mokona. Following Zagato's defeat, Clef witnesses Emeraude's death and later confesses his prior knowledge of the knights' true purpose.

During Cephiro's collapse post-Emeraude's death, Clef collaborates with other magicians to create a refuge castle. When the knights return, he reveals his remorse for his earlier secrecy and assists in defending against invading nations: Autozam, Fahren, and Chizeta. He advocates for transparency with future Pillar candidates to avert past tragedies. Later, he senses the emergence of the "Road to the Pillar," supports Hikaru's rejection of the Pillar system leading to Cephiro's reformation, aids Autozam's recovery, and researches ecological solutions for their world.

In the anime's second season, Clef exhausts himself casting powerful protective magic for the castle, nearly dying until Sierra intervenes. He deduces Debonair is the true enemy and investigates her through Alcyone. He evaluates potential Pillar candidates like Eagle Vision, recognizing Eagle's dedication to his homeland and illness, and promises aid to Autozam regardless of the Pillar outcome.

The OVA depicts Clef traveling to Earth.