"Professor Sycamore of Kalos has been leading the research on a mysterious new form of evolution. Mega Evolution powers up a Pokèmon during battle, causing it to take an entirely new and 'Mega Evolved' form. Unfortunately, not every Pokèmon has the ability to Mega Evolve. In fact, even if a Pokèmon has a possible Mega Evolved form, its Trainer must still possess three important things to enable his or her Pokèmon to Mega Evolve. First, the bond between the Trainer and their Pokèmon must be incredibly tight. They have to completely understand and support each other. Their teamwork and friendship must be as a solid as a rock. For example, the Gym Leader of Shalour City, Korrina, insisted she and her best friend, Lucario, win a hundred battles straight before they went to Geosenge Town to find Lucarionite - which brings us to the second thing a trainer must possess. Each Pokèmon that can possibly Mega Evolve requires a specific Mega Stone to transform. For example; for Garchomp it's Garchompite, for Blaziken it's Blazikenite and you get the idea. These rocks are so precious that they cannot be stolen or even taken by an undeserving person. Sorry, Team Rocket, no trap will get you this treasure! And you can't buy a Mega Stone from a merchant like you could an evolutionary stone. A Trainer must prove they have what it takes. It's something a special trainer must quest for. The third and final piece to unlock Mega Evolution is the Key Stone. Whether placed in a glove, strung on a necklace, set in a band or even pinned on a necktie, the Trainer must be wearing a key stone to help their Pokèmon Mega Evolve. This Key Stone links a trainer to his or her Pokèmon in a way that seems almost like a sixth sense. Using a Key Stone, a trainer can tell how his or her Pokèmon feels and see where it is without words. Once the Key Stone and Mega Stone are shown during a battle, the Pokèmon is encased in a cloud of miraculous light. Inside, it temporarily transforms into it's Mega Evolved form until it is able to battle, or until the battle is over. During this period, it is referred to by it's name, but with Mega as Prefix - like Mega Blaziken.

 POKÈMON MEGASTONE MEGA EVOLVED POKÈMON

 Abomasnow
 AbomasiteMega Abomasnow
Image result for mega abomasnow sprite
 Absol 
 Absolite
Mega Absol
Image result for mega absol sprite
 Aerodactyl
 AerodactyliteMega Aerodactyl
Image result for mega aerodactyl sprite
 AggronAggronite
Mega Aggron
Image result for mega aggron sprite
Alakazam
Alakazite
Mega Alakazam
Alakazam  sprite from X & Y
Altaria
Altarianite
Mega Altaria
Image result for mega altaria sprite
Ampharos
Ampharosite
Mega Ampharos
Image result for mega ampharos sprite
Audino
Audinite
Mega Audino
Audino  sprite from Omega Ruby & Alpha Sapphire
Banette
Banettite
Mega Banette
Image result for mega banette sprite
Beedrill
Beedrillite
Mega Beedrill
Image result for mega beedrill sprite
Blastoise
Blastoisinite
Mega Blastoise
Image result for mega blastoise sprite

Blaziken
Blazikenite
Mega Blaziken
Image result for mega blaziken sprite
Camerupt
Cameruptite
Mega Camerupt
Image result for mega camerupt sprite

Charizard X
Charizardite X
Mega Charizard X
Charizard  sprite from Omega Ruby & Alpha Sapphire
Charizard Y
Charizardite Y
Mega Charizard Y
Charizard  sprite from Omega Ruby & Alpha Sapphire
Diancie
Diancite
Mega Diancie
Image result for mega diancie sprite
Gallade
Galladite
Mega Gallade
Gallade  sprite from Omega Ruby & Alpha Sapphire
Garchomp
Garchompite
Mega Garchomp
Image result for mega garchomp sprite
Gardevoir
Gardevoirite
Mega Gardevoir
Image result for mega gardevoir sprite
Gengar
Gengarite
Mega Gengar
Gengar  sprite from Omega Ruby & Alpha Sapphire
Glalie
Glalitite
Mega Glalie
Image result for mega glalie sprite
Gyarados
Gyaradosite
Mega Gyarados
Image result for mega gyarados sprite
Heracross
Heracronite
Mega Heracross
Image result for mega heracross sprite
Houndoom
Houndoominite
Mega Houndoom
Image result for mega houndoom sprite
Kangaskhan
Kanghaskanite
Mega Kangaskhan
Image result for mega kangaskhan sprite
Latias
Latiasite
Mega Latias
Latias  sprite from Omega Ruby & Alpha Sapphire
Latios
Latiosite
Mega Latios
Latios  sprite from Omega Ruby & Alpha Sapphire
Lopunny
Lopunnite
Mega Lopunny  
Lopunny  sprite from Omega Ruby & Alpha Sapphire
Lucario
Lucarionite
Mega Lucario
Lucario  sprite from Omega Ruby & Alpha Sapphire
Manectric
Manectite
Mega Manectric
Manectric  sprite from Omega Ruby & Alpha Sapphire
Mawile
Mawilite
Mega Mawile
Mawile  sprite from Omega Ruby & Alpha Sapphire
Medicham
Medichamite
Mega Medicham
Medicham  sprite from Omega Ruby & Alpha Sapphire
Metagross
Metagrossite
Mega Metagross
Metagross  sprite from Omega Ruby & Alpha Sapphire
Mewtwo X
Mewtwonite X
Mega Mewtwo X
Mewtwo  sprite from Omega Ruby & Alpha Sapphire
Mewtwo Y
Mewtwonite Y
Mega Mewtwo Y
Mewtwo  sprite from Omega Ruby & Alpha Sapphire
Pidgeot
Pidgeotite
Mega Pidgeot
Pidgeot  sprite from Omega Ruby & Alpha Sapphire
Pinsir
Pinsirite
Mega Pinsir
Pinsir  sprite from Omega Ruby & Alpha Sapphire
Sableye
Sablenite
Mega Sableye
Sableye  sprite from Omega Ruby & Alpha Sapphire
Salamence
Salamencite
Mega Salamence
Salamence  sprite from Omega Ruby & Alpha Sapphire
Sceptile
Sceptilite
Mega Sceptile
Sceptile  sprite from Omega Ruby & Alpha Sapphire
Scizor
Scizorite
Mega Scizor
Scizor  sprite from Omega Ruby & Alpha Sapphire
Sharpedo
Sharpedonite
Mega Sharpedo
Sharpedo  sprite from Omega Ruby & Alpha Sapphire
Slowbro
Slowbronite
Mega Slowbro
Slowbro  sprite from Omega Ruby & Alpha Sapphire
Steelix
Steelixite
Mega Steelix
Steelix  sprite from Omega Ruby & Alpha Sapphire
Swampert
Swamperite
Mega Swampert
Swampert  sprite from Omega Ruby & Alpha Sapphire
Tyranitar
Tyranitarite
Mega Tyranitar
Tyranitar  sprite from Omega Ruby & Alpha Sapphire
Venusaur
Venusaurite
Mega Venusaur
Venusaur  sprite from Omega Ruby & Alpha Sapphire