Dualcaster Mage, Prison Break, and Yahenni, Undying Partisan

Prerequisites

• Dualcaster Mage in hand
• Prison Break in hand or in the graveyard
• Yahenni, Undying Partisan on the battlefield
• at most available

Steps

1. Cast Prison Break either from your hand by paying or from your graveyard for its mayhem cost by paying , targeting any applicable target
2. Holding priority, cast Dualcaster Mage by paying its mana cost
3. When Dualcaster Mage enters, it triggers, targeting Prison Break
4. Holding priority, activate Yahenni by sacrificing Dualcaster Mage
5. Resolve the Dualcaster Mage trigger, copying Prison Break, with the copy targeting Dualcaster Mage Resolve the Prison Break copy, returning Dualcaster Mage from your graveyard to the battlefield
6. Repeat from step 3

Results

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