Daughter of Dixon and member of the Alten Schwart mercenary brigade. Because of being surrounded by rough guys, she has a bit of a sharp tongue. She acts as an elder sister to Crevanille. Her mother objected to her becoming a mercenary and wished that she stayed home. But Regina was determined to follow her father. Their home was in Ribocca, Dulkheim.
When Dixon disbanded the mercenaries to investigate angels, Regina went with Dixon. They came to the Ruins of Hope in Dulkheim but were attacked by Vester. Vester struck Dixon fatally, and Regina attempted to fight him. Vester killed her as well.
She appeared alive again mysteriously at the Marquelay ruins but with a very different personality. Crevanille and Remus appeared incredulous to seeing her again, but she left without answering them.
When Maggie was going to use the spell cannon to shoot an angel, Regina came to defend her from Bryntir's attack. It appeared that her objective was to destroy angels. She started working for Valkania, teaching summon magic to the military.
She came to Eliza's villa to kill Maggie because Maggie studied ancient technology and could pose a threat. Crevanille's party defeated her. She begged them to finish her off while the power controlling her was weak. She revealed that she had a parasite implanted in her that allowed her body and mind to be controlled by Vester. If the parasite was removed, it would also kill Regina. Vester had replaced Regina's heart after he killed her to make her continue living, but was completely controlled by him.
She was seen at the spellcannon at Mount Baltrick, and fought to defend it. Once again she was defeated and she pleaded to be killed. But Crevanille and his familiar had the ability to enter her psyche and find out whatever was controlling her memories. She became free from Vester's control, but she would need a new heart to replace the parasite still in her body, or else she would die if Vester died.
Crevanille and Maggie found out how to create a heart with homunculus knowledge. Regina's heart transplant was successful.