Like most Magic: The Gathering cards, the value of Nazgl depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (The Lord of the Rings: Tales of Middle-earth)
This helps you in the long run, as when an opponent uses a spell or ability casts using mana from a Treasure, you put a +1/+1 counter on any creature and draw a card
This is an immensely powerful effect, especially in a black control deck (be it Commander or otherwise) that cares about dealing with any threat your opponent might have in their hand, on the board, in the graveyard anywhere
To do that, I'll need to phone some friends: Calling all Mill Guys
I think its one of the single best cards in any kind of black mirror, and I think it is perhaps the most important card you can put in your sideboard against the Supreme Verdict decks
Can You Pay an Alternate Cost and an Additional Cost at the Same Time