The Move Relearner is located within Mistralton City. In this house, to the right of the Pokémon Centre, the top right character is willing to teach your Pokémon any of the moves in its level up learnset that it has previously forgotten. For some Pokémon, this is the only way you can get some of the moves such as Victini with Fire Platform. This however, is not free, and costs you one Heart Scale per attack. Serbii
So no egg moves, tms, hms or move tutors.