How do you get a riolu in that game,I really want him!?

You have to go to Crystal Cave Clearing.Thee you will find a Riolu. It is a bit hard to recruit it but you can do it (especially if you have a Friend Ribbon)!

Hope this helps you out!

Its only found in the Crystal Cave at the clearing but it takes time and sometimes a long time if it wont come with you.

You can get Riolu through Crystal Crossing dungeon, if you look under recruitments with your options you can see what Pokemon are around that you can recruit, I've actually recruited 2 Riolu's Male and Female, the first one is lvl 90 somethin and is already evolved into Lucario with a Sun Ribbon. Not sure what Team Raider is suppose to do but it's gettin annoyin with them just sitting down at the beach even Team Charm had something to do like Aegis Cave where you go up against the regi's and Regigigas. Found some cheats earlier so i'ma go get Kyrogre, the one in Giant Volcano, Groundon, Mew,Articuno, Giratina, but first I'ma go get goodies to find Darkrai as well, Palkia likely knocked him silly like how the player is when you start out, at least thats what Palkia said.