Narset's Reversal, and Twincast

Prerequisites

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

Results

• Infinite magecraft triggers