If my growlithe learns flare blitz, for example, and I evolve it in to an Arcanine and delete that move, can I relearn it? Keep in mind he DID know this move at some point.
If you go to the move relearner, your Arcanine will be able to relearn any move that it has learned before, even moves it learned as a Growlithe. This works for all Pokemon. Note that the move relearner (in ORAS) won't let your Pokemon relearn moves unless you give him a heart scale.
Hope I helped!