Still, it troubled her that the girl had thought to use the fence like she had. She really didn’t like the idea that the villain had not only seen her face, but that she might have figured out one of her weaknesses. Two, if she counted the pepper spray. Being permeable was a problem when she absorbed gases, vapors and aerosols directly into her body. It wouldn’t affect her if she was in her shadow state, and it would eventually filter out, but if she were forced to change back, she’d suffer as badly as anyone, if not worse.

Sentinel 9.6