I might be reading too much into this but here goes. Assuming I have Black Market Prism Star in play. I have a Greninja Zoroark GX with a dark energy attached and 150 damage on it, then play Nanu to change it to an Yveltal with 110 HP. Does my opponent still take a prize? Black Market Prism text: When a [D] Pokémon (yours or your opponent’s) that has any [D] Energy attached to it is Knocked Out by damage from an opponent’s attack, that player takes 1 fewer Prize card. Does the pokemon getting KO'd count as being KO'd by the damage done from an opponent's attack? Assuming the 150 damage was placed by an opponent's attack originally.