I am not sure, but you can evolve a riolu from a riolu egg that Riley gave you in Iron Island. Sorry if this is a bad answer!
You can't catch Lucario in any game before Diamond/Pearl.
You can't lucario didn't exist until diamond, pearl, platinum came out which came after emerald.
You Cannot catch lucario on pokemon black the only Way is to trade him or catch a riolu.
He is in lots of different Pokemon games, like diamond and pearl.
you have to go iron island and find riely,then help him get to the end of the cave then he will give you a egg and it will hatch into a rilo then when you evolve it,it will be lucario
Lucario cannot be obtained in Pokemon Emerald, as it was not introduced until Pokemon Diamond, Pearl, and Platinum, which were released after Emerald.You can only get Lucario in 4th generation games such as Pokemon Diamond, Pokemon Pearl, and Pokemon Platinum.but it's cry sounds like it's from the 3rd generation
diamond or pearl or platinum.
If you have a lucario instead of trying to capture riolu why not breed lucario instead.
You can't get lucario in heartgold or soulsilver. You have to trade it from Diamond, Pearl or Platinum. Hope it Helped. Pokemon Master & Lucario Biologist. ~Bolt the lucario
NO you cant catch syther in Pokemon pearl
You can't catch a charizard in pokemon pearl.
Spiritomb Togekiss Lucario Garchomp Roserade Milotic