Just saw the leak regarding Zygarde. I think, by seeing this guy, he actually looks kind of neat. He has both the elements of a serpent and a shell-less slug, making it quite unique in terms of design.
For the rest, its noted he's a Dragon/Ground typing. Going to the myths of Norse Mythology about the World Serpent or even the dragon Nidhoggr that chews at the base of the World Tree Yggdrasil, this typing actually fits him. In other ways however, at the same time, the typing trolls Zygarde in that his types are completely useless to use against either Xerneas or Yveltal.
However, once more, it appears he trolls them back with his ability of Aura Break. The way the ability is described though, I think some people have mis-guessed its actual effect.
Aura Break:
(The effects of 'Aura' abilities are reversed)
Instead of reducing Fairy or Dark type moves, what if Zygarde's ability is about turning Xerneas and Yveltal's abilities against their own, weakening them, like decreasing the power of their respective Fairy and Dark-type moves? I mean, it says "reversed", and not anything like "negates moves" or such. He is the Order Pokémon after all. I could imagine this by having him weaken them greatly but without acutally doing that much damage. Perhaps its so great, that it reduces the powers of Xerneas and Yveltal to downright zero.
This might mean that any fairy or dark-type moves held by Xerneas and Yveltal become 0 BP, meaning that those moves won't do any damage against Zygarde, even if he was weak against Fairy. Of course, this is just a theory of mine. I could be completely wrong. IF this is true, then any Fairy type moves held by Xerneas or any Dark-type moves held by Yveltal become moves equal to the useless Splash move held by Magikarp, whenever its used against Zygarde.
As for moves, while its a Dragon/Ground typing, knowing about the new Dual-Type move system in the game, I wouldn't be too surprised if this guy had a Dual-Type signature move that does supereffective damage on both Fairy and Dark-Type Pokémon, like giving him a move that does both Poison/Electric damage, or Electric/Steel, etc, etc, etc. Since he's the Order Pokémon, this would make a lot of sense as he's keeping the balance. Also, in a way, the Ground typing is ironic: if his ability is truely what I say it is, this snake is effectively "grounding" them (pun intended), and the word "zero" could be a play on him representing the letter Z, if he's the letter Z (which I think he is).
Other than that, the only cons I can find so far, is that he could have been given a longer snake-like body, and that he has low stats, which seems to hint he will get a alternate form like Giratina or Kyurem did and thus be much stronger in the coming future.
