Requires

Spellweaver Volute must be on the battlefield. Pull from Eternity must be in the graveyard. Thousand-Year Storm must be on the battlefield. Petals of Insight must be in hand. Turnabout must be in the graveyard. Two additional instant cards in graveyard. Spellweaver Volute attached to Turnabout. You control lands that can tap to add at least . Mana needed:

Steps

1. Cast Petals of Insight by paying .
2. Thousand-Year Storm and Spellweaver Volute trigger.
3. Resolve Spellweaver Volute's trigger, casting a copy of Turnabout, exiling Turnabout, and attaching Spellweaver Volute to Pull from Eternity.
4. Thousand-Year Storm triggers, copying Turnabout for each other instant and sorcery spell you've cast before it this turn.
5. Activate your lands by tapping them to add mana.
6. Resolve a copy of Turnabout, untapping all lands you control.
7. Repeat the previous two steps for each remaining Turnabout on the stack, resulting in at least plus twelve generic mana available.
8. Resolve the remaining Thousand-Year Storm trigger, copying Petals of Insight for each other instant and sorcery spell you've cast before it this turn.
9. Resolve all non-card copies of Petals of Insight, drawing three cards for each one.
10. Resolve the original Petals of Insight, returning it to your hand.
11. Cast Petals of Insight by paying .
12. Thousand-Year Storm and Spellweaver Volute trigger.
13. Resolve Spellweaver Volute's trigger, casting a copy of Pull from Eternity, exiling Pull from Eternity, and attaching Spellweaver Volute to any instant card in your graveyard.
14. Thousand-Year Storm triggers, copying Pull from Eternity for each other instant and sorcery spell you've cast before it this turn.
15. Resolve all copies of Pull from Eternity, returning Pull from Eternity, Turnabout, and (if possible) any other instant card from exile to your graveyard.
16. Resolve the remaining Thousand-Year Storm trigger, copying Petals of Insight for each other instant and sorcery spell you've cast before it this turn.
17. Resolve all non-card copies of Petals of Insight, drawing three cards for each one.
18. Resolve the original Petals of Insight, returning it to your hand.
19. Cast Petals of Insight by paying .
20. Thousand-Year Storm and Spellweaver Volute trigger.
21. Resolve Spellweaver Volute's trigger, casting a copy of the instant it is attached to, exiling that instant card, and attaching Spellweaver Volute to Turnabout.
22. Thousand-Year Storm triggers, copying the instant for each other instant and sorcery spell you've cast before it this turn.
23. Resolve all copies of the instant.
24. Resolve the remaining Thousand-Year Storm trigger, copying Petals of Insight for each other instant or sorcery you've cast before it this turn.
25. Resolve all non-card copies of Petals of Insight, drawing three cards for each one.
26. Resolve the original Petals of Insight, returning it to your hand.
27. Repeat, choosing not to draw cards with Petals of Insight when needed to avoid losing the game.

Results