Mega Evolution
Mega Evolution is a Final Smash of Charizard and Lucario. It is based on the Mega Evolution system from Pokemon X and Y, which enhances Pokémon's power to a great margin. When a Pokémon holds a Mega Stone, it becomes capable of Mega Evolution; the number of Pokémon that are capable of Mega Evolution, however, is limited.
In Super Smash Bros. series, Mega Evolution appear as Final Smashes of both Lucario and Charizard. When either Charizard or Lucario gains the power of Smash Ball, it gains Mega Evolved forms that greatly enhances its power and grants invincibility to some extent.
Mega Lucario
As for Mega Lucario, its aura-based attacks will always strike at maximum power, regardless of its damage. The transformation only lasts for a short time period, however, and its duration gets shortened even further if Mega Lucario takes any damage. Unlike most Final Smash transformations, Mega Lucario maintains all the custom specials that its normal state has.
Mega Charizard
As for Mega Charizard, it gains the ability to fly, which is similar to Yoshi's Super Dragon. It has two attacks: Fire Blast, which allows it to shoot fireballs that spread into a kanji 大 upon contact, and Dragon Rush, which it rams into the opponents in a similar way to Flare Blitz move.
