Phyrexian Altar, Continue?, and Dualcaster Mage

Prerequisites

• Phyrexian Altar on the battlefield
• Continue? in hand
• Dualcaster Mage in hand
• available

Steps

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

Results

• Infinite ETB
• Infinite LTB
• Infinite colored mana
• Infinite death triggers
• Infinite magecraft triggers
• Infinite sacrifice triggers
• Infinite recursion of creatures you control