Thousand-Year Storm + Narset's Reversal + Turnabout

Prerequisites

Lands (or artifacts, or creatures) sufficient to produce {2}{U}{U}{U}{U}.

Steps

1. Cast Turnabout.
2. Thousand-Year Storm triggers.
3. Allow any Turnabout copies to resolve, maintaining the original.
4. Cast Narset's Reversal targeting Turnabout.
5. Thousand-Year Storm triggers.
6. Have at least one copy of Narset's Reversal target the original Narset's Reversal.
7. When that copy of Narset's Reversal resolves, target the original Turnabout with the new copy of Narset's Reversal created.
8. When that new copy of Narset's Reversal to resolves, target yourself with the copy of Turnabout.
9. When it resolves, untap all lands (or artifacts, or creatures) you control.
10. Repeat.