Theresa Rapual

is a nun and a former Magic Knight.

Biography
While working in the Royal Court, she is Fuegoreon Vermilion's magic instructor. After seeing the deaths of children on the battlefield, she becomes a nun so she can protect children.

Sister Lily goes to Theresia's church for training and, some time later, tells her about Asta.

After Marie plays with Asta, Theresia arrives to escort her back to the church. That night, the children of the town are kidnapped. Theresia senses mana in the snow and informs Gauche that Marie and other children have disappeared from the church. She decides to go with Gauche and Asta to rescue the children, and they depart on broomsticks. When they reach the caves, they spy Marco lying outside, and Gauche, not wanting to stop for anyone but Marie, drops Asta. Theresia lands to help the two boys. Asta frees Marco from enchantment with his broadsword, and Theresia heals him with Soothing Holy Light. Asta and Theresia make their way into the cave and confront Baro. Theresia discovers that the children have had their mana forcibly drained and may never be able to use magic.

Theresia watches as the two Magic Knights take on the brothers and is impressed with the Knights' abilities. She stops Asta from punching Baro and asks him to free the other enchanted children, after which she gathers them together and heals them. She yells at Gauche to stop kicking Neige, as they need to find how to reverse the mana drain. Theresia finds Sally's manga creepy and asks if she was one of the ones who attacked the castle. She destroys Sticky Salamander with Shining Flame Cross and attacks Sally with Fire Magic, freeing Asta.

Magic

 * Fire Magic: Theresia uses this form of magic to manipulate the element of fire.

Abilities

 * Mana Sensory: Theresia possesses the ability to sense mana in others and her surroundings.
 * Magic Power: While her mana is declining because of her age, Theresia can pull more mana from nature.

Equipment

 * Grimoire: Theresia possesses a grimoire, which contains fire-based spells that she could use during combat.

Gauche Adlai
Theresia sees Gauche as a bad influence on Marie and limits their interaction.

Fuegoreon Vermilion
As his mentor, Theresia developed affection for the boy, calling him. She holds him in high esteem and is proud of how far he has come.