Bianca

Bianca Without blood, Bianca is unable to fight, let alone function; a week after her last blood supply, she struggles to stand up straight. Once she gets enough blood again, she regains her strength, which makes her a "vampire" in her own right. She says she started having symptoms around the age of five, and the first time she drank blood was at the age of fourteen. That's nine years of blood deprivation. As her abilities grew, the amount of blood she needed increased, putting a strain on her second brother, who regularly donated blood.
Her VF is characterized by the fact that it reacts with blood: she can make someone bleed more heavily, or, conversely, she can make the blood clot and heal them. Not only that, but she also has some control over what's in the blood. Of course, it depends on the opponent's resistance and distance, so the effectiveness drops dramatically after a distance of about 3 meters.
(Bianca) is a test subject who doesn't mind living on the island, so she won't attack the researchers, but it's best not to get too close to her while she's still wounded.

Bianca was nearly killed in the past, but a priest named John saved her life and they have been allies ever since, and Bianca feels like she's been with family in the past, so she gave him her real name, and they've been relying on each other.