Let me just say something real quick regarding Lucario's ability of choice.
Lucario should always be carrying Justified, especially if it's holding Lucarionite.
Why? It should be obvious. Knock off is a very popular move, and almost everything that can use it has it, especially Dark Types. With Lucarionite, Lucario won't lose the item and get an a very threatening Attack boost from it, and since Lucario has Extremespeed, Bullet Punch, and Mach Punch as priority moves, it'll make the opponent very cautious of actually using Knock off at all. It does cause mind games, but they benefit you. From the possibility of switching your Lucario into Knock Off, it'll make the opponent hesitant to use it at all. And that's with just one possible mega on your team (this works for any tier Mega Lucario is allowed in. the circumstances of when Knock off is used differs, as in, I don't know if Knock Off is common in Ubers).
Just my two cents. TL;DR always use Justified because Knock Off.