Five Hundred Year Diary

The tension here is that this thing is a Clue that hoards Clues, and a Clue exists to be cracked. Every other Clue on your board carries a "2, Sacrifice: Draw a card" clause, and so does this one; its tap ability, meanwhile, rewards you for leaving every one of those tokens standing, scaling blue mana to the width of the pile. Because the Diary counts itself, it always taps for at least , and it grows with each additional Clue you refuse to spend. That is the pivot the card asks you to hold in your head: mana width and card draw are drawn from the same resource, and each Clue you crack for a card is a point of ramp you retired to do it. Entering tapped compounds the patience it demands, so the mana never arrives the turn you commit it; the card reads less as ramp than as an investment that pays across several turns. As a mana source it is peculiar in that its output is a function of your investigate output, which anchors it to decks already flooding the board with tokens rather than to any generic role as a rock. The Book type and the conceit of a diary that outlives its keeper are the era's crossover flavor, but the design underneath is a payoff that converts an artifact-token subtheme into blue mana without forcing you to surrender the cards those same tokens still promise.