Five keeps walking briskly down the hall, because it helps him think and he's tired of letting this drive him insane. If it worked, he wouldn't even have to consider what he's considering. But it's just a random artifact he lifted from a bank in some zombie-infested town. Winnie of course trails him, and he ignores her for several more steps before he responds.

"Didn't you hear me? It's useless." When he turns to look she's too close to him, and in a brief moment of panic he reflexively teleports several feet ahead.

His eyes are wild when he faces her again, and he makes a quick note of her hands and what she's doing with them. Jumping unfortunately upsets some sort of balance in him, and the curse works to pull away any sense of composure he had. For a moment all he can think about is getting it out, making it stop, and it takes exactly that long to realize he's still holding the mirror in his hands and she's still too close.

He'd like to say what he does next is rational; that he'd figured out that breaking the mirror was the next logical step. It's not. He sees Winnie move and reacts by throwing it with as much force as he can muster at the column nearest to her. He seems surprised when he hears the sound of glass shattering.

If he meant it as a threat or a warning, he doesn't follow it up with anything. He just stands there in temporary shock of how fragile it turned out to be.