Given this site's track record, 'major enough to last a whole day' IS 'slight'.
I probably mentioned it already, but I don't know if I mentioned it on this topic. This has always bugged me. I was never sure if I should put it in this topic, or the 'doesn't make sense' topic. Because this both annoys me to no end, and also doesn't make sense to me at the same time.
Seriously, what's the point of them? They're evolutions that a Pokémon can temporarily use in battle? Can't they already evolve? Why do we need them? How do the Mega Stones work? How can people even tell which ones work on which Pokémon? Why can only certain Pokémon use them? And for that matter, why didn't we know about them until Gen VI, despite the fact that Kalos has been using them this whole time and apparently they've existed all along? You're seriously telling me that no other Pokémon researcher or Professor bothered to check in with that Region's Professor to see if any advancements or new discoveries had been made? Isn't that supposed to be their job? What have they been doing this whole time?
Eh, did you skip the gen 6 games? Cause like half of your questions were explained ingame.