I like the idea, but the first two abilities are the same thing with different values, so there's no reason someone would use the second. Also, the memorize trigger would have to be "Memorize creature", so that it ensures only one creature is memorized per use. I'd also recommend making that ability either require a sacrifice of the enchantment, or a much higher cost and tapping the enchantment, since no sacrifice would allow really cheap copying of possibly very expensive creatures.
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