Requires

Riku of Two Reflections must be on the battlefield. Narset's Reversal must be in hand. Karn's Temporal Sundering must be in hand. Mana needed: each turn

Steps

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

Results