The official Japanese Pokemon Twitter has revealed Burning Energy from Red Flash. Thanks goes to Mia V. and Vincent H. for the translation!
Burning Energy – Special Energy
This card can only be attached to [R] Pokemon. This card provides [R] Energy only while this card is attached to a [R] Pokemon.
If this card is discarded by an effect of an attack of the [R] Pokemon this card is attached to, reattach this card to that Pokemon from your discard pile (after applying damage and effects from the attack).
(If this card is attached to anything other than a [R] Pokemon, discard this card.)