POKEMON GEN 6 ANNOUNCED

[NICKtendo DS]

It would have been interesting having to use it in-battle, so the player has to think whether it's worth it using a turn to evolve.

I think I would have been more accepting of the concept if this were the case. Particularly if the transformed state only lasted for so many turns. It would be similar to the armored modes in Mega Man: Command Mission, which I love.

As to the rest of your post: so each MegaEvolution has its own rock variety? Is that how this goes?

I've seen a screenshot with the word "Blazikenite" in it and one with "Lucarionite" in it. It's safe to assume there's an Ampharosite, Mewtwonite, Absolite and Mawilite.