Like most Magic: The Gathering cards, the value of Teferi, Mage of Zhalfir 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 (Final Fantasy: Through the Ages)
Likewise, this deck's draw power is limited to a single copy of Hiram Flaversham, Toymaker, two copies of Judy Hopps, Optimistic Officer, and a few Pawpsickles, which only replace themselves
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Comet comes into play with five loyalty and only has a single loyalty ability, which is worth zero loyalty
That gets way stronger with enchantments like Utopia Sprawl that allow your lands to tap for 1 or more mana or lands that innately tap for lots of mana, like Nykthos, Shrine to Nyx