Has to be a basic water. Double dragon and such are not a type until after you attach them to a pokemon. So the ability would not trigger.The card does not specify basic energy anywhere on it only W, so when attaching a rainbow, or unit or DDE, would that not activate it? Would DDE activate it twice, since it can be considered 2 water? What about prism star super boost energy? Could it heal 20, or even 80 if you have 3 stage 2s up?
Also, saying DDE is out of standard doesnt really mean anything, as this can still be used in expanded, and in Japan, where I play, DDE is still in "standard." Thanks for the reminder though!