Tiff's power of perception was wondrous indeed, even before this entire army, none of them bothered to look her way. Her power was actually better suited for such occasions, where attention was scattered and when you were ignoring certain things, it allowed her to become background noise all the more easily.
The problem with it, however, was that she wasn't actually invisible, instead people simply looked past her as if she was. The important difference in that seemingly semantic definition came into play when her wonderful Lord, in all of his Angelic Majesty, leapt over the approaching army like it was the most pitiful he had ever encountered.
While it wasn't something worth his effort, it was a massive obstacle for Tiff. She couldn't just push her way through as if she was invisible. Drawing attention to herself by touching, yelling or even just sprinting was enough to break the subtle spell over her.
