My understanding is that a "controller" is one of the players. I am trying to figure out whether the Charm card prevents attacks against the mage only (being an extension of the player), or against all of that player's cards in play, or against something else (for example, attacks against conjurations are ok whereas attacks against mage and creatures are not).
Any thoughts? The way I interpret it, this means that no card controlled by the charming mage can be attacked... but I am a new player, so I can't be certain.