Use soothe bell and feed it some poffins... make it happy and win battles simultaneously. it only evolves at day
riolu evlove into lucario at level 14.
first you go to ironisland and there is a cave then go through and there will be someone then he gives you a egg and you need only 5 Pokemon with you then it will hatch into a riolu then make it...
Riolu evolves through maxed out happiness. hope this helps
yeah but trin him on the day :)