Where does your rival go in pokemon pearl after stark mtn & after the fight area?!?

Ok in Pokemon Pearl, I beat the pkn league, then i went to stark mtn and my rival was there and I caught Heatron and he left. Then he was at the entrance to the battle tower, I beat him like 10 times, and now he isn't there. can anybody tell me where the heck he is?!?!!?!?!?!??!?!?!?