Honestly their just gimmicky and downright stupid. Some mons yes might become "broken" from them, but open their asses up to get ram. Hell unless there's a way to negate protect, detect, wide guard, quick guard etc with them I'll just bait idiots to use it and then blow them the fuck back. Seriously unless the Z-Crystals are consumable, which even with what they are saying doesn't seem like it, unless Unburden still considers it "used" it won't help mons like Unburden Sceptile or Hawlucha when Power Herb just does a better job for them.
Like seriously, this is what the fuckboys against Megas get. It's like there fucking pandering to people like Wolfe Glicke or something and even he's for Megas returning just more balanced.
Honestly this is just Game Freak's awkward attempt at bringing even more Pokemon fans back into fold- but they'll prove me right when they over do it and end up having some game-breaking glitch thanks to all their kid, gen 1, and mega-haters pandering. Or maybe it'll be as insanely cool as Pokemon Mystery Dungeon aka Furry is I, who the fuck knows.
