I don't see why Her signature move is getting so much hate. I hear to use her Z move you need to use this move. I haven't looking up what it does, wanna be a bit surprised, but I plan to use the Z cyrstal on this pokemon. Plus Aria I assume is sound based, so a surf that goes through substitues without having to use her hidden ability is nice.
I see her using Assault vest quite well actually. She has one of the highest Spc Attacks of water type pokemon, and decent special bulk, plus a good offensive move list.
Modest, Assault vest
Sparkling Aria
Moonblast
Energy Ball
Hyper Voice/Psychic
Hyper voice would hit more, but She is going to be on my team with Tapu Lele, so psychic is also a very valid option. I don't want to use Scald since I have a Salazzle, and I want to toxic everything.
I see a lot of people thinking of these pokemon by themselves, and not thinking on how they would fit on the specific team they are building.
EDIT: Derp I said I was gonna use the Z cyrstalk but listed assult vest. I guess it depends on how good her Z move is