Narset's Reversal, and Expansion // Explosion

Prerequisites

• Narset's Reversal in hand
• Expansion // Explosion in hand
• plus enough mana to cast the additional instant or sorcery available

Steps

1. Cast any instant or sorcery by paying its mana cost
2. Holding priority, cast Expansion by paying its mana cost, targeting the instant or sorcery cast in step 1
3. Cast Narset's Reversal by paying , copying Expansion targeting the spell cast in step 1 and returning the original Expansion to your hand
4. Cast Expansion by paying its mana cost, copying the copy of Expansion, targeting the copy of Expansion
5. Resolve the copy of Expansion, creating a copy of Expansion targeting the copy of Expansion
6. Repeat step 5

Results

• Infinite magecraft triggers