Dualcaster Mage, Dose of Dawnglow, and Yahenni, Undying Partisan

Prerequisites

• Dualcaster Mage in hand
• Dose of Dawnglow in hand
• Yahenni, Undying Partisan on the battlefield
• available

Steps

1. Cast Dose of Dawnglow by paying its mana cost Holding priority, cast Dualcaster Mage by paying its mana cost
2. When Dualcaster Mage enters, it triggers, targeting Dose of Dawnglow
3. Holding priority, activate Yahenni by sacrificing Dualcaster Mage
4. Resolve the Dualcaster Mage trigger, copying Dose of Dawnglow Resolve the Dose of Dawnglow copy, returning Dualcaster Mage from your graveyard to the battlefield
5. Repeat from step 3

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite magecraft triggers