I wanna battle my rival.

[WarHawk]

I beat the game and got the National Dex. I caught Heatran and all Legendaries.I faced my rival in front of the battle tower then the next day he's gone. Do I have to wait or do something to facing him.

[Hyunbin]

you probably got him on sunday
he only appears to battle on saturdays and sundays
one battle each day