Riku of Two Reflections + Narset's Reversal + Time Stretch
Riku of Two Reflections
Narset's Reversal
Time Stretch
Infinite turnsLock
How it works
Cast Time Stretch by paying 8.
Riku's first ability triggers - choose not to pay.
Holding priority, cast Narset's Reversal by paying , targeting Time Stretch.
Riku's first ability triggers, causing you to pay to copy Narset's Reversal, with the copy targeting the original Narset's Reversal.
Resolve the copy of Narset's Reversal, copying the original Narset's Reversal targeting Time Stretch, and returning the original Narset's Reversal to your hand.
Resolve the copy of Narset's Reversal created in step 5, copying Time Stretch and returning the original Time Stretch to your hand.
Resolve Time Stretch, causing you to take two extra turns after this one.