Dark Explorers is by no means lackluster. There's actually a good amount of cards in the set that can stand out in the new format. Allow us to take a look at these cards and see how they could impact the meta.
Raikou EX: This one is obvious. 100 Snipe + recharge with Eelektrik will be a force to be reckoned with, especially since it has only 1 retreat cost, which becomes free under Skyarrow Bridge; this potentially allows you to snipe with it every turn.
Darkrai EX: Will make dark decks playable because of the ability. It's also not bad as an attacker. The attack can be made even better through cards like Dark Patch, Darkness Claw, and Special Darks. It might have problems with Terrakion, but the next card is an answer too it.
Tornadus EX: Can hit for a turn 1 60 really easily and has an attack that hits for 100 without any major backlash. Fighting resistance makes it a decent option against Terrakion and other fighting types, making it a good partner with Darkrai EX and some Eel-based decks.
Empoleon- Mass attack returns, and it has its own built in draw power. It can be played with Terrakion to counter the lightning weakness.
Zoroark- Can potentially hit for 120 a turn with a DCE attached; it could also deal major damage with the second attack (if it has enough damage on it). Its basic stage, Zorua (which is part of the new set), also can evolve into Zoroark turn 1 thanks to Ascension.
Darkness Claw + Darkness Patch- Both of these cards will increase the playability of dark types. It offers a nice energy engine to dark types, and with special darks, you can mostly be hitting for an additional 30-40 damage from dark Pokemon like Zoroark and Darkrai EX (both require two dark type energies for their attacks). With these cards and Darkrai EX, I have some feeling we could see a dark type toolbox coming in soon.
Random Receiver- This is the new Pokegear. Why? There's always a chance that Pokegear can whiff on the supporters, and it does happen. With Random Receiver, you will always be guaranteed to hit a supporter, so expect this card to be a staple in decks.
Ultra Ball- Offers a new way to grab Pokemon out of the deck. Because you need to discard two cards from the deck, it won't necessarily replace Communication, but decks will most likely run 1-2 of this new Pokemon searcher.
Oh, and we get two very good reprints: Rare Candy and Pokemon Catcher.
So yeah, this set is definitely not lackluster. It is really quite decent.
EDIT: Oh yeah, I forgot another big card in the next set.
Heatmor: The #1 Counter to Durant. Drop only a single Heatmor, attach any basic energy you want to it, play nothing else (aside from another low-retreater and Skyarrow Bridge), and boom, hit away with its first attack to KO all Durants. Make sure you have any more basic energies in your hand just in case they Crush Hammer your own energy, and with that, you have one very effective Durant counter. Think of playing Heatmor like playing Terrakion against Durant. Drop only 1 Terrakion and nothing else and hit away. Likewise, do the same with Heatmor, and you are ready for Durant.
Raikou EX: This one is obvious. 100 Snipe + recharge with Eelektrik will be a force to be reckoned with, especially since it has only 1 retreat cost, which becomes free under Skyarrow Bridge; this potentially allows you to snipe with it every turn.
Darkrai EX: Will make dark decks playable because of the ability. It's also not bad as an attacker. The attack can be made even better through cards like Dark Patch, Darkness Claw, and Special Darks. It might have problems with Terrakion, but the next card is an answer too it.
Tornadus EX: Can hit for a turn 1 60 really easily and has an attack that hits for 100 without any major backlash. Fighting resistance makes it a decent option against Terrakion and other fighting types, making it a good partner with Darkrai EX and some Eel-based decks.
Empoleon- Mass attack returns, and it has its own built in draw power. It can be played with Terrakion to counter the lightning weakness.
Zoroark- Can potentially hit for 120 a turn with a DCE attached; it could also deal major damage with the second attack (if it has enough damage on it). Its basic stage, Zorua (which is part of the new set), also can evolve into Zoroark turn 1 thanks to Ascension.
Darkness Claw + Darkness Patch- Both of these cards will increase the playability of dark types. It offers a nice energy engine to dark types, and with special darks, you can mostly be hitting for an additional 30-40 damage from dark Pokemon like Zoroark and Darkrai EX (both require two dark type energies for their attacks). With these cards and Darkrai EX, I have some feeling we could see a dark type toolbox coming in soon.
Random Receiver- This is the new Pokegear. Why? There's always a chance that Pokegear can whiff on the supporters, and it does happen. With Random Receiver, you will always be guaranteed to hit a supporter, so expect this card to be a staple in decks.
Ultra Ball- Offers a new way to grab Pokemon out of the deck. Because you need to discard two cards from the deck, it won't necessarily replace Communication, but decks will most likely run 1-2 of this new Pokemon searcher.
Oh, and we get two very good reprints: Rare Candy and Pokemon Catcher.
So yeah, this set is definitely not lackluster. It is really quite decent.
EDIT: Oh yeah, I forgot another big card in the next set.
Heatmor: The #1 Counter to Durant. Drop only a single Heatmor, attach any basic energy you want to it, play nothing else (aside from another low-retreater and Skyarrow Bridge), and boom, hit away with its first attack to KO all Durants. Make sure you have any more basic energies in your hand just in case they Crush Hammer your own energy, and with that, you have one very effective Durant counter. Think of playing Heatmor like playing Terrakion against Durant. Drop only 1 Terrakion and nothing else and hit away. Likewise, do the same with Heatmor, and you are ready for Durant.