What are some of the cards, in your own opinion, that have made a large impact (good or bad) in the gaming environment (metagame) and why? Feel free to post past experiences you had with (or against) the card.
This does not have to be limited to the current metagame. You can go back as far as when the Pokémon TCG was first released.
To start off, I'll point out some of the more obvious and influential ones. Neo: Genesis Slowking was infamous due to a bad translation. In Japan, Mind Games would allow the player to flip a coin when Slowking was active and their opponent plays a trainer card. If they got heads, the card would be shuffled back into their deck. In English, Mind Games could be used anywhere in play. Because WOTC refused to errata the card, it became a popular card in many decks.
Super Energy Removal and Gust of Wind were staple cards in Haymaker decks. These decks quickly dominated the metagame because they disrupted and slowed other decks down.
This does not have to be limited to the current metagame. You can go back as far as when the Pokémon TCG was first released.
To start off, I'll point out some of the more obvious and influential ones. Neo: Genesis Slowking was infamous due to a bad translation. In Japan, Mind Games would allow the player to flip a coin when Slowking was active and their opponent plays a trainer card. If they got heads, the card would be shuffled back into their deck. In English, Mind Games could be used anywhere in play. Because WOTC refused to errata the card, it became a popular card in many decks.
Super Energy Removal and Gust of Wind were staple cards in Haymaker decks. These decks quickly dominated the metagame because they disrupted and slowed other decks down.