Lucario can Mega Evolve into Mega Lucario if it is holding a Lucarionite.
Mega Lucario is the first Mega Evolution that you get to use in Pokémon X and Pokémon Y when you battle Korrina and her own Mega Lucario to determine if you get to use the Mega Stone. By winning the battle you get the Mega Stone and you get to take the same Lucario with you!
Mega Lucario makes an appearance in Super Smash Bros. 3DS/Wii U as a playable character. In this form the power of Lucario's Aura attacks reaches its maximum, making it a dangerous character to go against.
Mega Lucario resides in the Uber tier of competitive battling. With a high 145 base Attack, a great ability in Adaptability, and a high 112 base Speed, Mega Lucario is capable of wreaking havoc on opposing teams. With Swords Dance and strong attacks like Close Combat and Iron Tail, Mega Lucario can become a frightening sweeper capable of taking advantage of stall staples like Ferrothorn and Blissey for set up opportunities while having strong priority in Bullet Punch to pick off weakened Geomancy Xerneas, ending its rampage prematurely. Despite this, Mega Lucario does have some flaws that inhibit it from being a dominant force. While its good defensive typing gives it immunity to Toxic and nifty resistances, Mega Lucario's paltry bulk gives it no chance to take advantage of those resistances. Its lack of bulk also makes it very difficult for it to set up on offensive and balance teams capable of easily taking Mega Lucario out. Mega Lucario also faces stiff competition from other Mega forms such as Mega Salamence that can bring even more sweeping ability without the glaring flaws that Mega Lucario possesses.
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