It turns cards like Merfolk SecretkeeperMerfolk Secretkeeper and Fractured SanityFractured Sanity into nukes of a mill spell, and allows Altar of the BroodAltar of the Brood, Ruin CrabRuin Crab and Hedron CrabHedron Crab to be absolute menaces
1Teshar, Ancestor's Apostle
If I have a deck of 100 cards, it is unlikely I'm holding the exact set of cards I need to win the game with when this hits the board
Anointed Procession ($45-$80) Probably too pricey to be in the deck, but another way overdue for a reprint
A free Char and two Lightning Bolts directed nearly however you want is great value, and can even be a great way to burn opponents down if they don't have enough creatures to hit
What makes it unique is the deckbuilding rule attached to it: You can run as many copies as you want, something you almost never see outside of cards like Relentless Rats or Shadowborn Apostle