The Pokémon TCG Pocket meta has been dominated by a small number of decks since launch, with Misty's water-type deck being a particularly frustrating opponent due to its reliance on coin flips. Despite the release of three expansions, instead of countering Misty decks, the latest expansion, Triumphant Light, has only strengthened them.
The issue isn't necessarily Misty's raw power, but the intensely luck-based nature of its core mechanic. Misty, a Supporter card, lets players flip coins to attach water-type energy to a chosen Pokémon for each heads. This can lead to wildly varying outcomes, from a complete waste of resources to an overwhelming early game advantage that can secure a turn one victory.
Several cards from subsequent expansions have exacerbated the problem. Vaporeon from Mythical Island allows energy manipulation, while Manaphy from Space-Time Smackdown adds even more water energy. Powerful Pokémon like Palkia ex and Gyarados ex further capitalize on this energy surplus, solidifying water decks' dominance.
Triumphant Light introduces Irida, another Supporter card that heals 40 damage from each Pokémon with attached water-type energy. This gives water decks significant recovery capabilities, previously a strength of grass-type decks. The combination of Misty, Manaphy, Vaporeon, and now Irida creates a nearly unstoppable force.
Some TCG experts suggest DeNA, the developer, added Irida to force deckbuilding choices, as the 20-card deck limit necessitates tough decisions. The abundance of strong water-type cards makes removing Misty for Irida a difficult choice, but many players have found ways to include both.
An upcoming in-game event, requiring five consecutive wins for the best reward, highlights the problem. The high likelihood of encountering overwhelmingly powerful, luck-based water decks makes achieving this feat significantly harder. Consequently, many players are considering using water decks themselves to improve their chances of winning. The dominance of water decks, therefore, is likely to persist.