Finale of Revelation

The Finale cycle attached a floor and a ceiling to the same card: cast it cheap for a modest, exiled Blue Sun's Zenith and move on, or bankroll it into a full reset. That second mode dictates every line of the design, and it is priced steeply. The ceiling triggers only when X reaches ten, which means paying , a true twelve mana on the turn; anything short of that just draws you the cards. Hit the threshold and the sorcery stops refilling and starts reloading: the graveyard shuffles back into the library before the draw resolves, so you draw off everything you have already spent rather than a thinning deck, then untap up to five lands to keep the chain alive, then shed the maximum hand size so nothing evaporates at cleanup. The exile-on-resolution clause is the counterweight to all that recursion; the shuffle would otherwise let the spell feed itself indefinitely, so the printing removes it from the game to cap the loop at a single enormous turn. Most X-draw spells hand you cards and leave sustainability your problem. This one hands you the cards, the untapped lands to keep casting, and the permission to hold everything, all in one resolution, so long as you can find the twelve mana to unlock it.