Even if Ai wasn't blind, she didn't think she could perceive Twilight standing behind her with her eyes. It was only through special spiritual awareness, like hers, that one would be able to discover her if she did not want to be seen.
In her spiritual awareness, Ai found the outline of a disconcerting presence whose very reality seemed to warp around her, making it difficult to maintain an awareness of her for long. She was like a ghost, and she did possess some ghostly abilities, like phasing through matter.
Twilight was tall, taller than her by half a head, with her whole body covered in tight attire and an obnoxious mask on her face. Her eyes emitted a light that Ai inferred as a fearful purple. Her figure was lean and athletic, always ready for swift movement at a moment's notice.