(Zero is even.) Whenever an opponent casts a spell with mana value of the chosen quality, choose one that hasnt been chosen Put a +1/+1 counter on Gollum
People have compared it to The One Ring, which isn't that far off if you focus solely on the card draw
Tiamat Tiamat is a straightforward, powerful Dragon commander: when she enters, you search your library for up to five different Dragons and put them into your hand
Then you can force each foe to exile-draw their first card drawn in their draw step which forces them to play catch up and really hurts control decks that flip over stuff like Counterspell
8 Jin-Gitaxis, Core Augur Jin-Gitaxias, Core Augur is a notorious Phyrexian creature who gives its controller an overwhelming advantage with cards and spells
There are the other versions of Sauron, Lidless Gaze, all the various Nazgl, and even a mono-black version of Shelob