This section contains old or outdated information, or has not been updated in a while. Please check the content of this section and update it as required. Specifically, it needs info on the card's release from the Sun & Moon expansion onward.
Darkness Energy was first released in the Diamond & Pearl set, as Darkness-type Pokémon were becoming more prevalent in the TCG by this point, much like their counterparts in the games. This was to counter the fact that both the old Darkness Energy and the old Metal Energy, originally released in Neo Genesis, were classified as Special Energy cards, meaning only four of them were allowed in a legal deck. Combined with their rarity, many players had to go to great lengths to mix in a few Darkness-types into their deck. With the release of the Basic Energy version of Darkness Energy, an unlimited number is now allowed in a deck, although there is no longer a specific advantage to using this version, unlike with the Special Energy counterpart.
During the BW era, this card was released as one of the BW-P Promotional cards, numbered 017/BW-P, and was included in a ten card random pack released during the February 2011 Gym Challenge. It was later awarded as number 033/BW-P alongside Zorua for those who participated in the March 2011 Open Challenge. It was reprinted again in the BW-P Promos, numbered 089/BW-P, as a winner's prize awarded to those who won various competitions at the Summer Carnival in Tokyo Tower from July 23 to August 28.
The first Japanese release of the basic Darkness Energy during the XY Era was the prints included in the Fennekin Half Decks of both the XY Beginning Set and the XY Beginning Set for Girls. In December 2013, a special Unnumbered XY-P Promotional print was released as part of a Lawson promotional campaign in which shoppers could obtain a special set of stamped basic Energies included within the Pokémon Coin Set. January 2014 saw the release of Darkness Energy within the Yveltal Half Deck featuring the Half Deck's Set Symbol.
Due to this card first being released after Basic Energy cards stopped listing illustrator credits in the Expedition Base Set, no known print of this card has a known illustrator. However, the artwork on the Special variation of this card is changed to that of artist Takumi Akabane, while this, the Basic version, retains the artwork by Milky Isobe from Neo Genesis.
The background for the HeartGold & SoulSilver variant has an outline of Umbreon.