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I would think the only stipulation would be it must first be activated on a Magician, not that the identifier must be maintained in order to keep it on that character. Or does Magic Charms technically have to deactivate and reactivate during the owners turn?
As in I can activate an artifact pile Art, do some other stuff during my prep phase, then return and activate a non-art pile Art?
Well I just got better at playing Redemption.