The Pokémon TCG: EX Unseen Forces expansion was released on August 22nd, 2005.

EX Unseen Forces

The EX Unseen Forces expansion for the Pokémon TCG is the largest set of the EX series yet! Over 140 cards of Pokémon from the Pokémon Gold and Silver Version video games will give you deck-building flexibility like never before. Whether it's the latest Legendary Pokémon, the mysterious Unown, or the unmatched power of the Pokémon-ex, EX Unseen Forces will push your playing skills to the next level!

Legendary Means Sight Long Unseen
Lugia, Ho-Oh, Raikou, Suicune, and Entei, the five legendary Pokémon in the Pokémon Gold and Silver version video games, have new versions of Pokémon cards in the EX Unseen Forces expansion. Lugia and Ho-Oh come in both standard and Pokémon-ex versions, too!

Lugia ex (105/115) is the most powerful Basic Pokémon yet released! Its 200-damage Elemental Blast attack only requires one Fire Energy, one Water Energy, and one Lightning Energy! You have to discard one of each of those types after using the attack, though. Lugia ex is best used with other Pokémon that let you move Energy around, such as Ampharos (1/115). Ampharos' Energy Connect attack lets you move basic Energy cards from your Benched Pokémon to your Active Pokémon, so Lugia ex can attack more often if Ampharos keeps sending basic Energy cards to it.

Even if Lugia ex doesn't have enough Energy, it still remains a threat. Its Silver Sparkle Poké-Body lets you flip a coin whenever your opponent's Attacking Pokémon does damage to your Lugia ex. If you get heads, you may discard one of the Attacking Pokémon?s attached Energy cards!

Ho-Oh ex (104/115) is arguably as powerful as Lugia ex. Ho-Oh ex's Rainbow Burn attack has a base damage of 10, but it gains 20 damage for each different basic Energy type attached to Ho-Oh ex. That means its maximum damage (not counting any other effects) is 130, and, unlike Lugia ex, you don't even have to discard anything! Ho-Oh ex will also find Ampharos to be an excellent teammate because of Ampharos' ability to attach basic Energy cards to Ho-Oh ex.

Both Lugia ex and Ho-Oh ex will also benefit from Smeargle (48/115). Smeargle's Makeover Poké-Power lets you switch a basic Energy card attached to one of your Pokémon with a basic Energy card in your discard pile. As long as you have basic Energy cards in your discard pile, Smeargle provides you with a way to ensure that you can get the best basic Energy cards for a particular situation.

Raikou (114/115), Entei (113/115), and Suicune(115/115) each has a 70-damage attack that requires only three Energy. But if you have fewer Prizes Cards left than your opponent, watch out: Raikou's Meta Voltage may do 40 damage to each of your Pokémon, Entei's Detonation forces you to discard the top ten cards on your deck, a nd Suicune's Cross Wind forces you to discard all Energy cards attached to all of your Pokémon! Fortunately, these Pokémon have secondary attacks that you can use when you have fewer Prize Cards left than your opponent. These secondary attacks let you switch them with one of your Benched Pokémon.

Unseen Forces, Hidden Powers
The EX Unseen Forces expansion contains 28 different Unown. Each is represented by a different letter of the alphabet, plus "!" and "?". Unown can switch itself with any of its other forms once per turn with the Shuffle Poké-Power. Also, each Unown has one unique Hidden Power attack. Taken together, these features mean that you can have up to four customized abilities for Unown in a single deck!

Let's pretend you have a deck that has three different types of Pokémon, and they all lead to Stage 1 or Stage 2 Evolutions. You might want to put an Unown (M) and an Unown (Q) in your deck. Unown (M)'s Hidden Power lets you search your deck for a card that evolves from one of your Pokémon and put it on that Pokémon. Unown (Q)'s Hidden Power attack lets you search your deck for up to three different types of basic Energy cards and put them in your hand. On one turn, Unown (Q) could get each of the basic Energy cards you would need for your Pokémon, and then on the next turn you could use Shuffle to switch Unown (Q) with Unown (M) and start evolving your Pokémon.

Since each card is named Unown, you are allowed a maximum of four per deck, but you can put multiple copies of the same Unown in your deck. With the example above, a deck could have two Unown (Q) and two Unown (M). However, it can be more fun and rewarding to have a mix of different Unown. Unown (?) is particularly fun, since its Hidden Power is a mini-game in which your opponent has to guess what kind of card (Energy, Pokémon, or Trainer) you put face-down on the table. If your opponent guesses wrong, you get to draw two cards.

Indispensable (and Fully Visible) Tools and Supporters
One of the best features about EX Unseen Forces is the introduction of six new Pokémon Tools. These Pokémon Tools will provide your Pokémon with additional capabilities far beyond the norm. There are also a couple of Supporters that are especially useful.

Curse Powder (80/115) puts three damage counters on the Attacking Pokémon if it Knocks Out the Active Pokémon that Curse Powder is attached to. Just make the Pokémon that Curse Powder into your Active Pokémon and wait for it to get Knocked Out by your opponent's Pokémon. Your other Pokémon can finish off the opponent's injured Pokémon. Curse Powder cannot be attached to Pokémon-ex, and it may only be attached to an Evolved Pokémon. Curse Powder's effect is very helpful when attached to teammates of Feraligatr ex (103/115) or Politoed ex, since Feraligatr ex and Politoed ex gain attack bonuses based on the damage counters on the opponent?s Pokémon.

Energy Root (83/115) gives a +20 HP boost to any Pokémon that it is attached to. It also turns off that Pokémon's Poké-Bodies and Poké-Powers. As a special restriction, it may be not be attached to a Pokémon-ex or a Pokémon with Dark or an owner in its name. Twenty extra HP are great for Pokémon like Forretress or the EX Deoxys Weezing (Ex Deoxys, 51/107), because it means those Pokémon can survive their self-destructive attacks (Pop and Liability). The deactivation of Poké-Bodies and Poké-Powers could be a bad idea for some Pokémon, but for Pokémon such as Typhlosion, it's great. Once Typhlosion has enough damage counters to do a lot of damage, you can attach an Energy Root to boost Typhlosion's HP up to 130, and Typhlosion's Burning Aura will no longer injure Typhlosion.

Protective Orb (90/115) can only be attached to Evolved Pokémon that are not Pokémon-ex, and the Pokémon it is attached to has no Weakness. This effect will really help the Pokémon that have Weakness to the types that are popular among other Pokémon TCG players. For example, if the players in your area like to use Water-type Pokémon, Protective Orb will help your Fire-type Pokémon survive longer. Protective Orb is a good alternative to Ancient Tomb (EX Hidden Legends, 87/101) because there are many more ways to get rid of Stadiums than there are to get rid of Pokémon Tools. Protective Orb also works on a Pokémon with an owner in its name, and Ancient Tomb does not.

The two Supporters in EX Unseen Forces are Mary's Request (86/115) and Professor Elm's Training Method (89/115). Mary's Request lets you draw one card, plus two more cards if you have no Stage 2 Pokémon in play. It's very effective at the start of a game, and if your deck has no Stage 2 Pokémon, it's actually effective throughout the whole game. Professor Elm's Training Method lets you search your deck for any Evolution card. Unlike the earlier Celio's Network (EX FireRed & LeafGreen, 88/112), Professor Elm's Training Method can pull out a Pokémon-ex from your deck, but it can't pull out a Basic Pokémon. Of course, there's nothing stopping you from building a deck that contains both types of Supporters. With four of each, you're sure to get your Evolution cards into play fast!

Source: https://www.pokemon.com/us/pokemon-tcg/ex-unseen-forces