A humanoid weapon of twins made at Task Force G's research lab by combining UFS and demon technology. Born from an egg injected with genes from various races, they are twins; the older sister being Yufie, and the younger sister being Sofie. Among all genes, the characteristics of an Oni were the most profound, but they also possess the power of vampires.

Yufie spoke with a soft, elegant and sophisticated tone, as she wore a blue leotard. "My sister, Sofie, and I, Yufie, will take you down."

Sofie spoke more brash and rowdy as she smirked with mischief. "Don't be fooled by our looks, or you'll get your ass kicked!"