Q. If I have an attack that says to discard a Fire Energy and a Water Energy, may I discard a single Rainbow Energy card or Multi Energy card to satisfy that requirement?
A. No, even though Rainbow and Multi provide all energy types simultaneously, they only provide one unit of energy. You can discard it for either the Fire or the Water, but you would still need to discard at least one additional card of the required type. (Dec 11, 2008 PUI Rules Team)
