ミラベル・アードルグ

Witch shaman.

One of the five witches handpicked by the demon Zenohemia over a decade ago. 

A shaman capable of controlling the four great spirits at will, she's also skilled in the creation and control of golems as well as the magics written in ancient languages. She has the appearance of a young girl because her body stopped ageing after she was bestowed with demonic possession. Although occasionally assertive, she's usually calm and level-headed. She sees matters with a detached air and a panoramic viewpoint.

She collects humans she takes a liking to from nearby towns and villages and confines them in her mansion (which she calls her "Castle") whereby the captives are treated like slaves.

 A child prodigy with elemental magic, she grew up in wealth and privilege. This changed when Zenohemia came and bestowed her with demonic possession. Her parents fled the family home and she was left alone in the giant mansion. Because of this, she frequently conscripts good-looking villagers to work for her. As a result of her demonic possession, she would callously kill any who earned her displeasure. 

After Gil and his party defeat and exorcise her, she is willing to atone for her crimes at the villagers' hands but Norn takes pity on her and requests she fight together with Gil's party to atone for her past sins. She accepts the offer and quickly establishes herself as the "brains" of the party, capable of ****ysing and solving complex problems. 

Although she lost her demonic powers, her latent talent with elemental magic remained intact allowing her to fight demons with the help of summoned spirits. 

She eventually finds and reconciles with her parents, but she chooses not to live with them even after Zenohemia has been defeated. As a mark of gratitude towards Gil for all he's done for her, she swears she will remain a demonslayer by his side for as long as she's alive. /