You could probably use something thats anti-Fairy (cuz why not?). Lucario's nice, but its frail, and its doesn't resist Fairy. Scizor is a good option (Aegislash is nice too, but let's try to not make your team too weak to one fo the most common attacking types):
-Scizor w/Choice Band, maybe Iron Plate or Metal Coat
Nature:Adamant
Ability: Techincian
EVs: 248 HP, 252 attack, 8 Sp.Defense
Moves: Bullet Punch, U-turn, Pursuit,
Superpower
or
-Scizor w/
Life Orb Leftovers
Nature: Adamant
Ability: Technician
EVs: 252 HP, 40 Attack, 216 Sp.Defense
Moves: Swords Dance, Bullet Punch, X-Scissor/Bug Bite (if you have a Gen 5 game)/Brick Break, Roost
or
-Scizor w/Life Orb
Nature: Adamant
Ability: Technician
EVs: 252 Attack, 252 Speed, 4 Sp.Defense
Moves: Swords Dance, Bullet Punch, X-Scissor/Bug Bite, Brick Break
Scizor works well with MegaZard X, since Scizor covers its Dragon and Fairy weaknesses, while Charizard has a 4x resist to Scizor's only weakness, Fire. It's also immune to burn, which Scizor's not fond of either.