At the end of the game you will end up back at your house. Your rivals sister will say she saw a Zoroark in a dream and asks you to investigate. You go to Victory Road and a Zoroark will be waiting. Start from the top and follow the trail down. From the Polemon League you go down to Victory Road. When you see the big stair case with the broken pillars take the skinny stairs and make a right after the second skinny sets of stairs you see. Zoroark will lead from there.