Why would you have more than one? It's not like mixing in different types of cards would impede or help memorization. Might as well only have one deck with everything in it and if you really urgently need to memorize something now just have it jump the queue or something
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You're messing with me! You're messing with me, aren't you!?
You're making fun of me, aren't you!? Aren't you!? You definitely are! I'll murder you!