Errant, Street Artist, Dramatic Reversal, and Narset's Reversal

Prerequisites

• Errant, Street Artist on the battlefield
• Dramatic Reversal in hand
• Narset's Reversal in hand
• Nonland permanents you control can tap to produce at least
• available

Steps

1. Activate all mana producing nonland permanents you control by tapping them, adding at least
2. Cast Dramatic Reversal by paying
3. Holding priority, cast Narset's Reversal by paying , creating a copy of Dramatic Reversal and returning Dramatic Reversal to your hand
4. Activate Errant by paying and tapping it, creating a copy of the Dramatic Reversal copy
5. Resolve the first Dramatic Reversal copy, untapping all nonland permanents you control
6. Activate all mana producing nonland permanents you control by tapping them, adding at least
7. Repeat from step 4

Results

• Infinite magecraft triggers
• Infinite mana nonland permanents you control can produce
• Infinite untap of nonland permanents you control