Haha, I knew I shouldn't have used the word "mirror".
That was only a reference to Hyroen's Mirror Quanta. It implies that the cards cost mark quanta. It would probably be better to use a more suitable word before "quartet".
When you play this card, they become pseudo-permanents in the appropriate quadrant of your mark slot. The effects do not activate when played; instead, they can be activated once per turn (after summoning sickness) by clicking the appropriate quadrant and clicking the appropriate quadrant of the mark. You can only activate 1 quadrant per turn (if you activate one quadrant, you cannot activate other quadrants in the same turn). Playing a card in a quadrant (1, 2, 3, or 4) already occupied will replace the card in the current quadrant. As the cards are not permanents, they are unaffected by PC, and in the current version of the game unaffected by all possible control.
Of course, this is just what I had in mind when I created the 4 cards. Suggestions to improve, or even completely change for the better, the game mechanic are welcome.
I'll read through the comments when I'm more clear-headed.