Answer 1

Oh, Cores are the thing that decks are based around. They are usually 1/2 Pokemon that work together well in a deck that really keep it flowing.
For example, In Reshiboar, the cores would be Reshiram and (ability) Emboar.
In Klingklang/Coballion it's, well, Klingklang and Coballion.
Darkrai or Mewtwo decks consist of Darkrai EX and Mewtwo EX.
Eels are Eelektross.
ETC

So yeah, pretty close to the video game. You build a deck around a strategy, and the Pokemon that carry out that strategy, and then construct the deck to better that strategy and make it flow correctly.

~Rio

Comments

Of course you knew this while nobody else did. +1

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I'm convinced that my answer, later moved to a comment by Sent_By_Ravens, made a path, indirectly, for a more direct answer. Therefore answering this unresolved question,~~~ not to discount Rio in any way, shape, or form.

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THANK YOU SO MUCH RIO!

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You might want to take "unresolved" out of the title now. ;P

@ Veteran, Yeah, but your answer was incorrect, so...

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Upon further review and with the aid of Rio's answer, I was incorrect. That does not mean that a more correct and direct answer will come.

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Lol, I wish this was on here so I could've answered it earlier. xD Sorry 'bout dat.