Mega Evolution Possibilities

Lucario is one of the few Pokemon who received a Mega Evolution- a temporary in-battle evolution that awakens the inner beast, so to speak. Now that he has returned to Smash Bros., will his Mega Evolution have any appearance? And what, exactly?

There are numerous possibilities, from being an Alt. Costume to Mega Evolving for his final smash, and so on. What do you guys think? Should his Mega Evolution be present? If so,...

Mega Evolution Possibilities