There are some Pokémon which haven't been seen in Pokemon X and Y normally.Check their Photos.
Diancie:

Hoopa:

Now Legendaries:
Volcanion:

Latios/Latias:
Not confirmed if its Latias or Latios:

Oh my god where did you find all this? This is freakin' badass!

Was just Googling but aren't the legendary Awesome?
There is Mew also present in the game.

What the heck?!!!!!!!!!!!!!!!!!!!!!!
Mew!!!!!!!!!?!!!!!!!?????????

Yes.I didn't add the mew's image because it was not looking good.(Low quality Pic)

Hmm. So all these Pokemon are in Pokemon Village no?

Don't know.Just copied the pics.I thought you know them.

Never. Though I heared about Hoopa somewhere.

I heard about Diancie and Hoopa but never saw them before.Diancie is evolved form of Carbink.
Hoopa is Ghost Psychic Type Pokemon

Carbink huh.

Yes Carbink it is.

Cool!

Indeed it is.

Indeed it is.