Guile, and Flusterstorm

Prerequisites

• Guile on the battlefield
• Flusterstorm in hand
• You have an additional instant or sorcery card in hand
• plus enough mana to cast the instant or sorcery card available

Steps

1. Cast the additional instant or sorcery spell
2. Holding priority, cast Flusterstorm by paying , targeting the instant or sorcery
3. Flusterstorm's storm ability triggers, creating a copy of Flusterstorm for each spell you've cast before it this turn, with each copy targeting the original Flusterstorm
4. Resolve a copy of Flusterstorm, exiling Flusterstorm and allowing you to cast it from exile without paying its mana cost, targeting the instant or sorcery spell
5. Repeat from step 3

Results

• Infinite magecraft triggers
• Infinite storm count