The wording on repeat seems a little ambiguous to me when it comes to Elemental Boon and Gift of Nature's power. It says that Repeating a Power lets you activate its effect again. It does not give you Elements again (you gain Elements for putting a Power Card in play, not for using its effect) and Repears cannot be chained (ignore any "Repeat" effects on a Repeated Power)
If I were to Repeat Elemental Boon or Gift of Nature would it give Elements again because those are part of the effect not part of playing the Power. If you can, those cards are particularly powerful for Downpour Drenches the World. Do the two behave differently because of the way the Elements are listed on the right hand side of the card?