Croix Meridies is the new teacher of Modern Magic in Luna Nova Academy and an old acquaintance of Ursula.
Croix is a skilled manipulator who can be very charming when needed and stay uncannily cool under pressure. She is clearly an intelligent woman, having pioneered the field of Magitronics. She's a highly logical person who plans her actions carefully.
While she plans out her actions meticulously, she does not think about how her "experiments" will affect others, nor does she care. However, Croix is not completely monstrous nor heartless, as while she is determined to ruin Ursula's dreams as shown in "Wagandea," she was genuinely panicking when her robots made Chariot fall unconscious on her broom and nearly plummet to her death, and Croix's cries to awaken Chariot save her life.

In the past, she was shown to be kinder and more considerate, but seeing her dream stolen by Chariot led her to become a selfish and calculating person.

Towards the end of the series, Croix's personality changes after Chariot saves her life from being eaten by the Noir Rod despite everything Croix had put her through. Croix becomes a kind and considerate person, like she used to be, and eventually makes up with Chariot, telling her she'll devote herself to finding a cure for the Wagandea curse and restore Chariot's broom flying ability.
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