Riku of Two Reflections, Narset's Reversal, and Part the Waterveil

Prerequisites

• Riku of Two Reflections on the battlefield
• Narset's Reversal in hand
• Part the Waterveil in hand
• each turn available

Steps

1. Cast Part the Waterveil by paying
2. Riku's first ability triggers - choose not to pay
3. Holding priority, cast Narset's Reversal by paying , targeting Part the Waterveil
4. Riku's first ability triggers, causing you to pay to copy Narset's Reversal, with the copy targeting the original Narset's Reversal
5. Resolve the copy of Narset's Reversal, copying the original Narset's Reversal targeting Part the Waterveil, and returning the original Narset's Reversal to your hand
6. Resolve the copy of Narset's Reversal created in step 5, copying Part the Waterveil and returning the original Part the Waterveil to your hand
7. Resolve Part the Waterveil, causing you to take an extra turn after this one
8. Repeat each turn

Results

• Infinite turns