Mafia 90. The Tale of Oldforest.

To be more precise, it describes a single non-damaging spell, but then it describes how the character's ability is applied to themselves, if it is displayed.
9. Cause Confusion - Witch. (Displayed) so that the answer to the question is understood correctly.

The fact that the Confusion spell was used on Ment is displayed. Something like a temporary clouding of the mind (the Witch makes good tea^_^). Then, if Ment were to cast a spell that is displayed, it would show him applying it to himself. But he probably didn't do anything. Or maybe he's a werewolf, and the Guardian swapped him with Neira, and the Witch was causing confusion on her o_O
But that's very, very unlikely, so let's just imagine that I didn't say that, and the witch just went to the police officer to test a new tea.