I am a player, and i'm totally amazing at the game. I can't remember how many cards i had at the last count, but its over 1000 easily.
I've made this immense Green/White Deck, not using specific rules or anything for deck making (like Type 2, 1.5, 1 or anything), but not too many rare cards either, due to the cards i actually have. Armodillo cloak is an amazing card in my deck, as you stick it on anything of a decent size, and its game over, for three mana really. Most effective is with either Charging Troll or Trained Armodon i think, mainly because the former is immense too (regenerate for a green, as well as not tapping to attack (can't remember the name of that ability in the newer blocks)), and the latter is a 3/3 for 3 mana, which can't be bad.