I may be doing a poor job to describe this and I apologize if I am. I read on serebii Lucario can only learn nasty plot as Riolu (at level 47). But if he evolves BEFORE he hits level 47, can the move tutor still teach Lucario the move??
Actually, I think i did mean move relearner (I thought that he and the move tutor were the same person). In that case you've already answered my question.