Neo Destiny introduced a new classification for Pokémon cards (Light), expanded on another relatively new class (Shining), and brought back an older classification (Dark). So today I'm going to briefly explain the upsides and downsides of each of these archetypes.
Dark - A Fan-Favorite Archetype
The oldest of these classifications is the Dark Pokémon, not to be confused with Darkness-type Pokémon. The original concept behind these cards is that they were raised by Team Rocket and represent Pokémon that were only raised for battle.
They have low HP, probably because they weren't treated well, but usually have powerful attacks or Pokémon Powers to compensate.
These cards need to be extremely powerful to be worth using, though, since the miserable HP stats are really hard to overcome. Examples include Dark Crobat, who does damage just by entering play, and the older Dark Vileplume, who shuts off all Trainer Cards.
They seem to have noticed the issues with the Dark archetype eventually, as evidenced by Rocket's Hideout, a card from Neo Revelation that raises the HP of all Dark Pokémon in play by a flat 20.
There were surprisingly few cards to support the archetype in the WotC era, though. So it was rare to play a whole deck themed around the archetype. Instead, the individual cards would see play if they just happened to be powerful enough on their own merits.
Dark Pokémon would eventually get another shot in the EX Team Rocket Returns expansion, which abandoned their low HP gimmick and instead associated them with the Darkness-type.
This was a clever way to revisit the old archetype and support an underrepresented type at the same time. While these cards are ultimately completely unrelated to the ones from the WotC era, they deserve a mention any time the mechanic is brought up.
Light - A Failed Experiment
Light Pokémon were more about offering supportive effects, like healing and searching. The general theme uniting them was that they had helpful personalities, so the effects of the cards were meant to reflect that.
This might involve a simultaneous effect that benefits both players, to show off how fair they were, or it might involve attacks where the attacker would "hold back" under certain conditions, such as Light Arcanine's Gentle Flames.
As you can imagine, "being fair" and "holding back" didn't appeal very much to competitive players. This mechanic never saw the light of day again after this brief experiment.
Shining - A Gimmick Among Gimmicks
In order to represent the new shiny Pokémon mechanic from the mainline series, the Shining cards were created. (Even though "shiny" was only considered a fan-made term for a very long time.)
Neo Revelation kicked off this mechanic with Shining Magikarp and Shining Gyarados. They set the standard for the mechanic moving forward.
A Shining Pokémon is always a Basic, regardless of what the species should normally be, and has expensive multicolored attack costs. You can only include a single copy of each Shining Pokémon in your deck.
Miracle Energy, from Neo Destiny, seems to have been designed to help get around the extreme energy costs. It grants two energy that count as every type, but only for a single turn. Unfortunately, committing more deck space to a gimmick like this only made the mechanic even more unplayable.
Their compromise was to make this Special Energy work with both the Shining and the Light cards...but we've already established that the Light cards weren't actually very good.
Some of the Shining cards were decently playable, though, like Shining Raichu. Thundersquall is a powerful attack for the cost, and Water and Lightning were both solid types.
But a Shining Pokémon would usually be an addition to your deck, not the main strategy. It's unwise to commit too much thought and deck space to a card that you can only run a single copy of.
This mechanic may have had potential, but it ultimately never received the support it would have needed to flourish. I do think that's just as well, though, since these were clearly meant to be collectibles rather than serious game pieces.
The Success Stories
While these archetypes didn't all land on their feet, there were a few cards that deserve a brief pause to appreciate them. The obvious standout for the Dark mechanic is Dark Vileplume, largely because it was one of the most powerful floodgates ever printed.
Entire decks were focused around locking the opponent out of the game, and this card was likely one of the driving forces behind the gradual move towards having powerful support effects on 'mons, since cards like Cleffa can play under the lock.
Dark Weezing is probably the second-most prominent of the first wave (excluding Dark Golbat, who only became relevant because of another card we'll soon discuss).
This is a good example of the archetype actually achieving what it sets out to do. Mass Explosion is so unbelievably powerful that it justifies the low HP of Dark Weezing. This is a good representation of what Dark cards were supposed to do.
Dark Crobat was pretty solidly the best of the Dark cards released in Neo Destiny and instantly gave rise to an entire playstyle.
The general flow of the deck is that it spams Dark Golbat and Dark Crobat in order to do damage over and over with their oppressive Surprise Bite and Sneak Attack.
This deck greatly benefitted from the prevalence of Babies, since the combination of Sneak Attack and Surprise Bite just happens to do exactly 30 damage.
While I'm always quick to talk trash about the Light cards, Light Dragonite was actually a modest success. It has high HP, an above-rate attack, and a meta-relevant power that lets it shut off the effects of Special Energy cards.
It's especially damaging to Darkness and Metal decks, since all of their energy came from Special Energy cards. This allowed it to see play as a surprisingly debilitating counter-pick.
Note that it doesn't share the "fairness" that ruins many other Light cards.
Light Golduck is the one other card that stands out amidst the mostly mediocre Light cards. With the prevalence of Special Energy, Core Blast can actually do massive damage as early as the second turn.
The opponent only has to attach a single Special Energy in order to be taking 50 damage from Core Blast. Even if they play around it, that just means you're forcing suboptimal plays with a card that's already at a reasonable power level without this upside.
Not all good Dark cards were Grass-types. Dark Gengar is an incredible card for decks focused on sleep, since it forces the opponent to flip two coins to wake up instead of one. This can turn sleep into a self-contained lockdown strategy, and it isn't even the best thing about the card.
The true value of Dark Gengar comes from Pull In, which allows it to grab a Baby from the bench and smack it to take a prize right away. There are entire decks focused around abusing this interaction.
Closing Thoughts
Of these three gimmicks, only the Light mechanic was completely abandoned, and for good reason. Phrases like "do less damage" and "your opponent may draw a card" don't exactly sell packs. The Pokémon Trading Card Game is, at its core, a PvP competitive game. There's no inherent merit in an "everyone wins" playstyle and they failed to justify the mechanic in their designs.
The Dark mechanic, as previously mentioned, was ultimately redesigned from the ground up and rereleased in a future set. This redesign abandoned everything that didn't work and leaned into everything that did work, while adding support for the underrepresented Darkness type.
As for Shining Pokémon, the concept of "once-per-deck" restrictions would live on in several mechanics, such as the Radiant, Gold Star, and Prism Star cards. The expensive attacks would briefly live on in the upcoming Crystal mechanic, but would once again be poorly executed and abandoned.
Still, every failed experiment is just a step towards the next success, so we shouldn't dwell too long on mechanics that didn't work. These temporary failures and setbacks have an important place in the game's history, and the designers usually do a good job of capitalizing on the parts that worked as time goes on.
