At the beginning of your upkeep, put a time counter on As Foretold.
Once each turn, you may payrather than pay the mana cost for a spell you cast with converted mana cost X or less, where X is the number of time counters on As Foretold.
4/18/2017 If you cast a card for an alternative cost of , you can’t pay any other alternative costs, such as emerge costs. You can, however, pay additional costs. If the card has any mandatory additional costs, such as that of Tormenting Voice, you must pay those to cast the card.
4/18/2017 A card’s converted mana cost is determined solely by the mana symbols printed in its upper right corner. The converted mana cost is the total amount of mana in that cost, regardless of color. For example, a card with mana cost has converted mana cost 3. Ignore any alternative costs, additional costs, cost increases, or cost reductions that could apply to it. A card with no mana cost has a converted mana cost of 0.
4/18/2017 If a spell has no mana cost, its converted mana cost is 0. You can cast it with As Foretold’s alternative cost.
4/18/2017 If you’re casting a split card, only the converted mana cost of the half you’re casting is compared to the number of time counters on As Foretold. This is because only that half is on the stack at the time that you choose to apply the effect of As Foretold.
4/18/2017 If the card has X in its mana cost, you must choose 0 as the value of X when casting it for another cost that doesn’t include X. For example, if there are five time counters on As Foretold and you choose to use its effect to cast Pull from Tomorrow, X must be 0. X can’t be 2, even though the spell’s converted mana cost would be 4.
4/18/2017 If you control multiple As Foretolds, you may cast one spell for each of them paying .
4/18/2017 All counters with the same name are indistinguishable from other counters with that name. Cards from the Time Spiral block that interact with time counters will interact with As Foretold.