Nexus of Fateweaving

Whenever you cast a spell, you may pay {2}. If you
do,exile that spell instead of putting it into your graveyard as it resolves and put a Fate counter on
Nexus of Fateweaving.
{t}, Remove X Fate counters from Nexus of Fateweaving: You may cast a card with mana value
X exiled with Nexus of Fateweaving without paying its mana cost. X can't be 0.