So many conflicting opinions on this throughout the web. But I just tested this on the TCGO and it seems you are right. Just about a month ago I was playing Yveltal/Maxie's and someone used Rare Candy to cut through Ancient Power, though, so it looks like this is a recent change? And of course, the TCGO sometimes has bugs that don't reflect official rulings. Could you tell me when this new ruling came into effect? Or any other more specific details on this? Considering how popular Greninja has become in Expanded, it's definitely something we'd all like to be clear on.