One of the more unique aspects of RS-PK is Holon's Pokémon, a set of five Pokémon that can be played as Energy cards.

Holon's Castform/Electrode/Magneton Interactions

For brevity, I will refer to these as "bounce Energies".

• If you attach a bounce Energy to a Pokémon with no other Energy attached, the bounce Energy will bounce itself.

• Crystal Beach causes them to only provide {C}. Their bounce effects still happen.

• If you have 7 cards in your hand, which includes a bounce Energy and Steven's Advice, playing the bounce Energy keeps your hand at 7, so you must find some other way to reduce your hand size in order to use Steven's Advice.

• You can attach a bounce Energy to return another Energy with a when-attached effect (e.g. Heal Energy) to reuse that effect.

• You can attach a bounce Energy to return another Energy that was previously attached out of necessity, but would be better saved for something else (e.g. Scramble Energy).

• You can attach a bounce Energy to return Double Rainbow Energy, essentially giving up your Energy attachment for the turn, but removing the -10 damage drawback.

• You can attach a bounce Energy and return itself to trigger things like Island Cave or Arcanine ex's Fire Remedy, retaining the bounce Energy in hand so you have a guaranteed way to trigger those effects again on subsequent turns. Again, this essentially costs your Energy attachment for the turn.

• Be careful of returning Energy that provide passive effects to the attached Pokémon, such as Darkness, Metal, or Holon Energies (or the required basic Energies for them).

• A trick that's specific to the Manectric ex deck is using Mega Shot with a bounce Energy and a Multi Energy attached. At that moment, Multi Energy provides {C}, so it will not be discarded. All other combinations of Energy that can pay for Mega Shot (3 Lightning, bounce + Lightning, Multi + 2 Lightning) will result in all the Energy being discarded.

Which Holon's Pokémon?

Like with choosing the Basic Pokémon in your main Evolution line, the choice of Holon's Pokémon might seem insignificant, but there are small edges to be gained from choosing one over another.

Holon's Voltorb vs Holon's Magnemite

Being Basics, you run the risk of being forced to start with them, so which is less bad to start with?

• Holon's Voltorb has a better attack (though it's still very weak). If your deck can pay for either attack (e.g. Banette ex, which plays Rainbow Energy), Holon's Voltorb would be preferred.

• With regard to Weakness against common starters, Holon's Voltorb can get KOed on your opponent's second turn if they start with Exeggcute δ, Larvitar, or Machop, and hit the T1 Energy attachment. Holon's Magnemite can get KOed T2 by Larvitar δ, Numel, Growlithe, or Ralts δ (the last needing 2 attachments).

• Holon's Magnemite has a useful Resistance against Dragonite ex δ.

The Lanette Factor

If you play Lanette's Net Search, your choice of Holon's Pokémon can end up clashing with other Basic search targets in your deck. Coincidentally, all three Basic Holon's Pokémon share types with the staple setup Basics: Magnemite with Jirachi, Voltorb with Pidgey δ, and Castform with Pidgey. Not a lot of decks play Lanette's Net Search, though; even the ones that are hungry for Basics can get by just increasing their Holon Mentor and Pokémon Retriever count.

Holon's Electrode vs Holon's Magneton

Unlike the Basics, you can't be forced to start with them, or even put them down with Unown E. However, there are some cards that can make use of them as Pokémon in your hand...

• Alakazam ☆ can Skill Copy their attacks. In this case, Holon's Magneton would be preferred, as it can 1HKO Psychic-weak ex's like Lugia ex or Mew ex.

• An opposing Shiftry ex can Skill Hack their attacks from your hand. If you don't play any ex's, then Holon's Magneton is strictly better. If you do play ex's, then it's a matter of which is worse, a Dark-type attack that hits for 50, or 30 + Confusion. As an example, Arcanine ex would take the 30 + Confusion any day, since its Poké-Body cures Special Conditions anyway. Banette ex would also prefer taking Dazzle Blast, since Extra Ball 1HKOs it after applying Weakness.

Evolution...?

You might be wondering, "is it worth switching up the Holon's Pokémon I use in order to try to get an Electrode or Magneton down on the field?" The answer is no, overwhelmingly no. Just build how the deckbuilding principles tell you to, and don't compromise them for some corner-case play which in all likelihood will never materialize.

• Some decks are going to Mentor more than once per game because they need Holon's Castform as Energy, e.g. Gardevoir, Blastoise ex, Meganium. Swapping out Castform for Electrode on the off chance that you will be able to evolve Voltorb into Electrode makes no sense, because you can't Mentor for Electrode.

• Some decks (e.g. Arcanine ex) want to attack quickly on T2 with a Stage 1 ex, and will play 4 Professor Elm's Training Method to maximize their odds of setting that up, but also include a Holon's Electrode as a search target for late-game Elms. If you add Holon's Voltorb to try to chase the Evolution, that increases the risk of opening with a bad Basic.

• Holon's Voltorb/Magnemite often ends up getting discarded early to pay for retreat. Is it worth spending Pokémon Retriever on them so they can be reused for Evolution? Probably not.

• Do you have a plan for what you're going to do with a Holon's Electrode/Magneton on the field? If you have Pidgeot or Latios ex δ, those already act as 0 Retreat pivots, so Electrode loses its niche. If you're attacking with them, can you hit the colors consistently for their attacks, and do they beat stuff that your main attacker doesn't? Extra Ball's 2 Energy for 50 damage is above rate, but Magneton still ends up losing a lot of 1v1s against ex's because they can hit back for 70+ damage.