As fans immerse themselves into Pokemon X and Y, rumors and theories on Pokemon Z has already begun.

Ever since the announcement of Pokemon X and Y, rumors on Pokemon Z have been swirling online. But with the existence of the legendary Pokemon Zygarde, fans have developed interesting rumors on what the sequel might entail.

"Xerneas and Yveltal are both immune to Zygarde's main types," writes CoolGlaceon on PokeJungle.

"What if in Pokemon Z when and if Zygarde mega evolves, it gains an ability which turns immunities into weaknesses much like how inverse battles work. I guess this is also backed up by the fact that the only place to have inverse battles is on Route 18 where Terminus Cave is located…where Zygarde is found."

This is not the first time rumors of a Zygarde mega evolution has surfaced.

"A mega evolution gives a Pokemon an increase in 100 to their total base stats. Zygarde has 600 base stats which is super low for a [legendary trio]. A mega would make Zygarde have a 700 base stat, tying it with Mega Tyranitar and Mega Garchomp and making it stronger than Xerneas and Yveltal," writes HeavyMetalLamb.

"Its Pokedex also talks of how it will reveal its secret power when the ecosystem goes wrong, which I'm sure will be the plotline of the next game, and we manage to get ahold of Zygardenite which they will code into the next game of DLC expansion."

"Also, you ever notice how when you first encounter Xerneas it's in a tree-like-state, Yveltal is in a cocoon-like-state, and Zygarde looks like the larvae for a fly and lives underground like larvae."

Given the upcoming Diancie distribution, it is clear Game Freak intends expand the Pokemon X and Y universe, whether through a DLC or a sequel game like Pokemon Z.

What do you think of these Zygarde theories for Pokemon Z?