All of that depends on whether you're using Xerneas and/or Yveltal. And whether you have way too much dark or fairy-type moves. Aura Break seems really easy to get around as is, just use a non-dark or a non-fairy type move! :0
But yeah I was mostly talking thematically. Like, Zygarde is the pokemon of order, and balances out life and death in a neutral way by not affecting either of them, but putting them in check with its ability. Chaos pokemon, on the other hand, would most likely be strong against either of them while having an ability that either makes it easy to be taken advantage of or serves only to support itself. Or so that's my theory, anyways.
This is true, but since we're talking about Zygarde vs. Yveltal/Xerneas I assume a set-up as such.
Using a non-Dark/Fairy move means that you're not hitting it's obvious weakness, hence it offers some degree of protection, don't you think?
- I don't believe we know the multiplier for Fairy Aura.
- It could be a reverse addition (subtraction), which would be -50%, sure. It could also be a reversed (or rather, inversed) multiplier, which be -33% instead. Game Freak usually prefers multipliers over adding another term, but that's not absolutely.
I would assume that the multiplier would be the same, to unbalance them both would be silly, unless of course they're considering that fact to not make a Fairy-team as powerful.
We can't be entirely sure, however for them to say "reversed" alone implies that one of these calculations is present, and in doing so makes Zygarde a lot more appealing than just to have him negate the effects, you can't deny that.
Correct me if I'm wrong here. Assuming the auras have a 1.5x boost:
Regular Super Effective = 2x damage
Regular STAB Super Effective -> 1.5 x 2 = 3x damage
Aura Boosted STAB Super Effective -> 1.5 x 1.5 x 2 = 4.5x damage
Aura Reversed Super Effective -> 2 / 1.5 = 1.3x damage
Aura Reversed STAB Super Effective -> 1.5 x 2 / 1.5 = 2x damage (which is what a non-STAB move would normally do.)
So assuming Zygarde's ability reverses the auras, Xerneas and Yveltal just lose STAB against Zygarde, would still probably hurt. Assuming this applies to everyone in the party, basically anything that uses Fairy/Dark STAB just loses it. This would only really affect anything that isn't a Fairy/Dark type using moves of those types.
I'm assuming that when either X/Y or Z dies, everything should go back to normal though.
Assuming STAB is lost, and that all that is dealt is SE damage at x2, that's certainly better than being hit x3 or x4.5, I think despite Zygarde still being weak, it can be used tactically.
Furthermore, as you say, it would reduce SE damage to x1.3 from non-STAB candidates, thus making other Dark/Fairy users without Dark/Fairy typing effectively hit it for near-normal damage.
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In the end, I'm not trying to suggest that Zygarde is going to be something to be scared of, however, underestimating your opponent is never a good thing.
Plus, I figure this would be a good thing to bring up, as I saw people glaze over Zygarde's ability as a simple "negate".