Ok, this situation happened to me at the finals of a BR I went to. My opponent has 2 Basic Fire Energy and 1 DRE attached to his Active Infernape and uses Mega Bravo. He only discards the 2 Fire energy (Mega Bravo says discard all Fire Energy attached to Infernape) for 70 damaga to KO my Chatot MD. I call the Head Judge over and ask if he had to discard the DRE because it clearly provides fire energy. The judge ruled that the DRE didn't provide fire energy at that time so it wasn't discarded. So the question is... If you use Mega Bravo on Infernape and you have 2 basic fire energy and a DRE, do you have to discard all of do you have the choice to discard the 2 Fire energy and leave the DRE on the Infernape?