Fury Storm, and Twinning Staff

Prerequisites

• Fury Storm in hand
• Twinning Staff on the battlefield
• You have cast your commander from the command zone at least once
• available

Steps

1. Cast any other instant or sorcery by paying its mana cost, or wait for an opponent to cast one
2. Holding priority, cast Fury Storm by paying , targeting the instant or sorcery spell
3. Fury Storm triggers, creating a copy of Fury Storm for each time you've cast your commander this game plus an additional copy, with one copy targeting Fury Storm and all remaining copies targeting another instant or sorcery on the stack
4. Resolve the copy of Fury Storm that is targeting Fury Storm, creating two copies of Fury Storm, with one copy targeting Fury Storm and the remaining copy targeting another instant or sorcery on the stack
5. Repeat from step 4

Results

• Infinite copies of any instant and/or sorcery spells on the stack
• Infinite magecraft triggers