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I (and many other TwitchPlaysPokemon viewers) recently saw someone Mega Evolve a Diancie during a link battle. The video should still be archived on Twitch, but finding it would be tricky... [[User:HyperHacker|⬡]] ([[User talk:HyperHacker|talk]]) 15:27, 8 August 2014 (UTC)
:This is not currently possible in X and Y. It was likely footage from ORAS trailers. If you could provide the actual video though, it would be much easier to evaluate. --[[User:SnorlaxMonster|<span style="color:#A70000">'''Snorlax'''</span>]][[User talk:SnorlaxMonster|<span style="color:#0000A7">'''Monster'''</span>]] 15:58, 8 August 2014 (UTC)