I'll preface this tip by suggesting it could possibly be considered a very minor spoiler, so if you don't want future given items spoiled, skip this advice. Still here? Good! One Mega Evolution-able Pokémon is none other than fan favourite Lucario. If your absolutely dying to get your hands on one, and considering using a party slot to train one up, there is a much simpler method. Once Mega Evolution becomes available, Lucario will be given to you, at a good level for that section of the game (32). Not only that, but this Lucario already knows TM#98, Power Punch, a pretty decent Fighting move only applicable by TM. It also has it's very own Lucarionite needed for Mega Evolution... Win! Why Fairy is a type to be reckoned with, useful features to note, and one easy to obtain badass bird on page 2!