If Zeraora uses Plasma fists, and in the same turn Sylveon uses a Normal type move like Hyper Voice, what happens? Plasma Fists turns all Normal type moves into Electric type, and Pixilate turns all Normal type moves into Fairy type. So will Hyper Voice be turned into an Electric type move or Fairy type?
Hyper voice will be a fairy type move, because pixilate makes it fairy type before plasma fists activates its effect, so hyper voice is no longer a normal move to become electric.
Source: Tried it myself in battle