"As long as I'm with my elder brothers... it'll be fine."
BlazBlue: Calamity Trigger (non-playable)
Saya (サヤ) is the younger sister of Ragna the Bloodedge and Jin Kisaragi. She was kidnapped by Yuuki Terumi and became the vessel for Izanami. She was the basis for the Murakumo Units, specifically Lambda-11, Mu-12, and Nu-13.
As a young girl, Saya had shoulder length blonde hair and large green eyes. She has fair skin, and was often seen wearing a plain, white strapped dress.
After having her body surrendered to Hades Izanami, Saya's appearance took a hugely drastic change. Aside from the differences attributed to age, Saya's hair took on royal purple hue that reaches down to her lower back; her eyes also changed from green to a crimson red with many black circles layering them. Her attire became much more like an empress as she now wears an elegant golden headdress with a golden band to keep her hair in place. As Izanami, Saya wears a white kimono with elongated sleeves, and a red and yellow skirt that reaches down to her feet. Around her waist she wears a cyan bow while also wearing a black cape over her entire body; said cape has multiple purple bands reaching around her figure, complementing the royal attire.
When she was a child, Saya was kind and loving towards her siblings, and showed affection to the Sister despite the short time they spent together. These feelings remain untainted by Izanami's possession, as they still exist for Ragna, although little else is shown of what she is like.
Powers and Abilities
Saya has an incredible amount of Ars Magus aptitude, which is the suggested reason that she was placed in the Sister's care. Also, her body has the unique ability to near-infinitely amplify seithr. Additionally, Saya's willpower is extraordinary as her emotions remain to struggle against Izanami's control despite the time spent in her current state.
As of Izanami's possession, Saya now has untold power and is immortal to a technique which strips opponents of the time they have left in the world. Combined with the little-to-no effects present on her while wielding the Gigant: Take-Mikazuchi.
BlazBlue: Central Fiction Library Entry
Ragna and Jin's younger sister, who also happens to be Imperator of the NOL. She's physically weak, but her aptitude for Ars Magus is beyond compare. She was raised by the Sister in an area that had little seithr.
After being discovered by Yuuki Terumi, she is turned into the basis for Boundary Interface Prime Field Devices. 
BlazBlue 10th Anniversary Official Site Profile
Ragna and Jin's younger sister. She lived together with her two older brothers and the Sister, who was a parent to them, but Terumi attacked the church and killed the Sister, kidnapping the young Saya and Jin. 
- BlazBlue 10th Anniversary Site (JP), Saya
- BlazBlue: Central Fiction, Library Mode, Character #053