Since the foils were only announced a few days ago, I suspect most of you havent actually taken a good look at the list yet
Anytime an opponent casts a spell with mana value equal to the number you pick, or they cast a creature with either power or toughness equal to the number you picked, that player loses two life and you get to draw a card
It's not a huge amount of value, but when you consider the fact that you have three opponents, plus anything you do, you can draw upwards of four cards and make four tokens by the time your turn comes back around
Simic (green/blue) has access to a ton of protection and counterspells.
You can get more of these counters by sacrificing Eldrazi scion tokens, and they dont go away even if Azlask, the Swelling Scourge is removed
Itll probably fuel a strong Exsanguinate every now and again