From the looks of it Aya pulled off one hell of a move. She clasped both hands BEHIND the sword that's coming at her and PULLED it towards her while leaning back, causing the sword to slash harmlessly over her, pulling it out of Momiji's hands, AND giving her the opportunity to gutkick Momiji with those tengu-geta (Ouch, Momiji...). She might be a jerk in this doujin, but she's one skilled jerk.