Your argument is a very poor one. I could pull the same argument you are using with Nymphs, rare cards, or even upgraded cards. That gap you are talking about is nonexistent because if it only affect 1 in 100 games, that's not a noticeable gap. I can only interpret this thread as you having been scorned by a mark card in some way. maybe you were one away from winning a tournament, or you played a quanta denial/lock down deck in PvP and one person had a mark card and made it so your strategy worked just a little bit less, but they ultimately ended up winning. This is the very first thread I have ever seen about mark cards and their uber rarity being any sort of problem. Other threads about it might exist, but they are extremely rare. The main point is that mark cards offer such a small advantage there almost isn't one, so why make them less rare when they are just useful for boasting?