Garruk, Primal Hunter A planeswalker that can steadily build an army of 3/3s on a plus ability is already powerful, and Garruk, Primal Hunters minus ability can draw ta bunch of cards if you control a large creature
Green cards are commonly seen as the color of creatures and lands, since green's uniquely good at ramping and tends to get the fattest creatures to use all that extra mana on
Any opponent can pay five life to counter this effect so youre still down a creature
If you're curious to know which Commander Masters cards are the ones worth keeping (or the ones worth selling, if you're of the more mercantile mindset), then this list will provide you with an easy point of reference
Collector's Boosters The big one, collector's boosters are the most expensive of the four main booster pack types
Your lands arent affected, so thats already a good way to hate only your opponents