After the Iron Island side-plot you can meet Riley at the Battleground in the Survival Area.
Riley will give you and egg on Iron Island
You have to have the HM Strength which you can find on Iron Island with Riley.
Go to Iron Island and talk to Riley, he'll give it to you.
riley gives you an egg and it hatches into riolu it evolves into lucario with friendship you find riley on iron ball island.
After the Iron Island side-plot you can meet Riley at the Battleground in the Survival Area.
you get it from Riley from iron island ,from Jesse and Ryan Termaat
riley is at the iron island if you go with him at the end he will give you a egg
Riley gives it to you at iron island
Iron Island
you go to iron island and talk to someone named riley and you get strength and then you go and train with her.
You get it from Riley on Iron Island.find it the solecean ruins
Well, how should i descibe it? You can meet Riley only on Iron Island. He'll ask you to help him through the Island, trying to find out who is disturbing the Pokemon of Iron Island. After battling two Galactic Grunts (who were disturbing the Pokemon), Riley asks you if you want a Pokemon egg. Inside the egg is Riolu, who evolves into Lucario, but if you don't have room in your party, Riley will wait right there at Iron Island until you take the egg. After you leave Iron Island, Riley will, too. You can only see him in the Battle Tower after that event.
You find him on iron island in the cave
You get a Riolu egg after helping Riley at Iron Island
Riley gives it to you at Iron Island's cave entrance.
An egg, witch contains a Riley. It will evolve to a Lucario