If someone had a Sylveon with the ability Pixilate, would they have it hold a Silk Scarf or a Pixie Plate to make Hyper Voice stronger?
Silk Scarf is only for Normal moves. Pixilate makes Normal moves into Fairy, so they aren't Normal type moves anymore. You would have to hold a Pixie Plate. It would first turn into a Fairy-type move, then get the Pixilate boost, and then the Pixie Plate boost.
Source: My Sylveon from my Mono-Fairy team on PS!