Let's say Lanturn's your active, and you're facing a Chansey ex for example. You have a DRE and a Lightning energy attached to Lanturn. You use Lightning Strike and wish to do 90 damage, which means you need to discard. Since the attack costs (L)(*)(*), and you have a Lightning attached to it, then all you would really need to discard is the Lightning energy since the DRE can count as something else right?