?Suika is the only oni currently living above ground in Gensokyo, with the remainder of the oni race living underground. Just as the folktales say, she has two horns on her head that symbolize her oni heritage, and enough physical strength to throw large boulders single-handedly. Her personality is jolly and quite childish as you would expect from her appearance. She also likes to drink and loves to party with all her heart.
During the events of Immaterial and Missing Power, the people of Gensokyo were manipulated into having feasts repeatedly, one right after another, by Suika's ability. She intended to draw all the other oni out of hiding with continuous, non-stop celebration. In most characters' scenarios, Suika was defeated and the number of feasts began to decrease. In Suika's scenario, she managed to defeat all of her major foes in a feast, but her plan failed anyway due to Reimu's ability and her own incompleteness as an oni.
Suika is jolly and drink loving. Innocent and simple-minded. She raises an upbeat atmosphere in a crowd, but when you're alone with her, you'll gradually become irritated by her childishness.
Her ability allows her to control density. She can gather and scatter whatever she desires. By gathering people's sentiments, they will have parties; by scattering herself, she can become as mist.