How can you create a combo with Thousand-Year Storm, Narset's Reversal, Turnabout?
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[START OF COMBO]This combo can be formed with Thousand-Year Storm, Narset's Reversal, Turnabout

Color identity: UR
Mana cost: 
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.
  11. 
  12. [END OF COMBO STEPS]

Result:
  - Infinite colored mana
  - Infinite colorless mana
  - Infinite storm count
  - Infinite untap[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - Thousand-Year Storm must be on the battlefield
  - Narset's Reversal must be in your hand
  - Turnabout must be in your hand
  - Lands (or artifacts, or creatures) sufficient to produce {2}{U}{U}{U}{U}.
[END OF COMBO PREREQUISITES]
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