Was also looking for an answer to this, since I was gonna post that the visuals in PVP are a little out of hand and. You can't turn them off either.
I've tried. (excl. PVP) means just that...no way to show none of the other players attacks.
Take a look at the Character Config screen if you wanna see what I'm talking about.
I play the rest of the game with my own effects on, my party with some, and others on NONE for a reason. Way too much going on otherwise. Then you throw 72 players all smashing each other with explosions and flashy attacks in PVP...I can only play so many matches before my eyes and head start hurting. This is how I survive Bozja, Eureka, Alliance raids, Hunts....etc. PVP needs to give us the option as well.