Zaffai, Thunder Conductor, Dual Casting, and Intruder Alarm

Prerequisites

• Zaffai, Thunder Conductor on the battlefield
• Dual Casting on the battlefield
• Intruder Alarm on the battlefield
• Dual Casting attached to a creature without summoning sickness
• You have an instant or sorcery card in hand with mana value five or greater, and enough mana to cast it
• Creatures you control can tap to produce at least

Steps

1. Cast any instant or sorcery with mana value five or greater by paying its mana cost
2. Zaffai triggers, causing you to scry 1 and create a 4/4 Elemental creature token
3. The Elemental enters the battlefield, triggering Intruder Alarm, untapping all creatures
4. Activate all mana-producing creatures you control by tapping them, adding at least
5. Activate the creature with Dual Casting attached by paying and tapping it, copying the instant or sorcery spell you cast
6. Repeat from step 2

Results

• Infinite copies of any instants and/or sorceries you cast
• Infinite creature tokens
• Infinite ETB
• Infinite magecraft triggers
• Infinite mana creatures you control can produce
• Infinite scry 1
• Infinite untap of all creatures