She is the main character of the Saint Seiya: Saintia Shou manga. She is the Equuleus Saintia.
Shou is the younger sister of the previous Equuleus Saintia, Kyouko. She is also the host of Eris the Goddess of Discord.
Her main technique, Equuleus Ryūsei Ken, is very similar to Pegasus Ryūsei Ken.
(Source: Seiyapedia)