Power to control supernatural phenomena
Long, straight blonde hair, red eyes, and a single red horn coming out of her forehead. Wears a white, short-sleeved shirt with red trim at the cuffs, neck, and bottom and a dark blue translucent skirt with red highlights and trim. Her wrists and ankles are manacled, with short, broken chains attached to the manacles.
Yuugi is an oni. Like other oni, she's ridiculously strong and likes strong people. Also like other oni, she drinks heavily and enjoys raising a ruckus. She, along with Suika, was one of four particularly feared oni long ago. She rushes off to meet an intruder in the underground Ancient City, once part of Hell, and, impressed by their strength, agrees to lead them to the Palace of Earth Spirits if they'll fight her.
(All credit for description goes to the Touhou Wiki http://touhou.wikia.com/wiki/Yuugi_Hoshiguma )