Lucario 63 - Your best bet is Flying as the Steel negates it's weakness to Psychic (Not to say it doesn't work...just not super effective)
Not rly, best bet is Infernape because Lucario is weak against fire and fighting type because it's part steel.
That isn't really true. Using a flying type to resist Lucario's moves will work. But Infernape will only get maimed by Earthquake or Psychic depending on which one Lucario feels like using. Also Lucario's attack, special attack, and speed are all quite high.