Z Moves won't be that good in my opinion.
I can't say this for certain, but you basically can only use it once and if you have a move of the same type learned already. It takes nothing for the opponent to predict it, and make you waste a turn AND an item, the latter being what holds back most mega evolutions, so it's absolutely nothing to underestimate.
Now think about this
>>27494517, this is the most useful scenario we can come up with now, yet it also has many flaws. Dragon is usually not a super good type to use if you don't have STAB, as it doesn't have much type effectiveness. However if the move is extremely powerful, like, pre Gen 5 Explosion, that wouldn't matter much. Still it's a huge drawback, some set up sweepers could use it to break once against some walls they never managed to defeat, but again they will lose Life Orb for the ability to hit one Pokémon very hard once, it's hard to settle on this. Again we need to know how powerful these moves will be.
If they are as devasting as Explosion, as I said before, they would be absolutely game changing in doubles. There Pokémon usually don't abuse offensive items too much and rather go for more safe options like Sitrus, Herbs, utility stuff likely. Since Protect/Substitute and Detect are omnipresent, this basically give Explosion to everybody with little drawbacks. Imprison can just take care of the rest of the Protects. They might even be so strong that you can't protect against them, though that's a bit too much in my opinion.
>>27495321Not confirmed, that said if that's true I'm a bit sad because megas made some of my bros good, but I hope megas officially die, they were so unbalanced overall, they ruined everything.
