Thats a very good effect, especially for decks like Charizard ex which have high retreat costs and otherwise cant justify burning energy on retreating, but it has another effect if you read between the lines
This ratio is present for foils and nonfoils, which is an interesting surprise
Others flip single cards when they first appear in a new set, which can be a bit of a game in itself
Additionally, his secondary class is Survivor, which has tons of cards built for comeback from botched skill tests or to face the impossible odds
It can single-handedly wipe your opponents board of monsters with its ability to attack each creature once each turn, and can keep your gameplan going by throwing down even more Memento monsters in response to your opponent trying to activate card effects
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