Lady Shiori is encountered approximately halfway through the level. Despite her status as a mini-boss, she considered one of the most dangerous and difficult enemies to face. The main danger lies in her gaze. If Sinjid is facing Lady Shiori when she uses it, he will be stunned and can take upwards of 1000 damage. Will usually, then fire an array of magic-based projectiles, which do heavy damage while Sinjid is stunned.
Sinjid can avoid her gaze by turning away from her when she prepares to use it. He will not be stunned, and will take a severely reduced amount of damage. A good way to dodge her projectiles is to run back and forth underneath her. Keeping her within sight is another priority. This to tell when she is using her gaze and prepare accordingly.