So I've looked this up, but I couldn't find any info about it. Say I'm in doubles. I send out Sylveon (with pixelate) and slaking. Slaking uses giga impact. Does giga impact get turned into a fairy move or does pixelate only affect sylveon's moves?
Pixilate
Pixilate causes all Normal-type attacking moves used by the ability-bearer to become Fairy-type.
Aerilate
Aerilate causes all Normal-type attacking moves used by the ability-bearer to become Flying-type.
Refrigerate
Refrigerate causes all Normal-type attacking moves used by the ability-bearer to become Ice-type.
As is the case with all three -ate abilities, only the ability-bearer has it's attacks' type changed. Therefore, Slacking's Giga Impact will not become Fairy type.
No giga impact will remain a normal type move only the Pokemon with the ability aerilate, pixelate, or refrigerate will turn that move into a flying, fairy, or ice move. The only way it could is if it was skill swapped or entrainment on to it