Elodie, even as you ready yourself to inflict terrible damage upon an evil ghost, something catches your eye. Masque is indeed whispering those things in dear little Timmy's ear, and that is unambiguously the sort of thing Masque as a wicked shapeshifter would do... 

But there are two forces there, not one. Something that was already inside Timothy is seeping out of him and mingling with and overlaying Masque. Some evil spirit must have gotten to him before all of this. Not the sort of thing you can affect with your magic, but perhaps the sort of hex Annalee might know how to handle - if she wasn't the one responsible for it in the first place.