Wrath of the Skies

If an effect says you get one or more {E}, you get that many energy counters. To pay one or more {E}, you lose that many energy counters. You can't pay more energy counters than you have. Any effects that interact with counters a player gets, has, or loses can interact with energy counters.

Choosing not to pay any {E} will have the same result as choosing to pay zero {E}. In either of these cases, each artifact, creature, and enchantment with a mana value of 0 will be destroyed.

Energy counters are a kind of counter that a player may have. They're not associated with any specific permanents.

Keep track of how many energy counters each player has. Potential ways to track this include writing theme down on paper or using dice, but any method that is clear and mutually agreeable is fine. (At higher levels of tournament play, dice may not be allowed for tracking counters that players have.)

If a spell or ability with one or more targets states that you "may pay" some amount of {E}, and each permanent that it targets has become an illegal target, the spell or ability won't resolve. You can't pay any {E} even if you want to.

Some triggered abilities state that you "may pay" a certain amount of {E}. You can't pay that amount multiple times to multiply the effect. You simply choose whether or not to pay that amount of {E} as the ability resolves.