Phyrexian Altar, Demonic Gifts, and Dualcaster Mage

Prerequisites

• Phyrexian Altar on the battlefield
• Demonic Gifts in hand
• Dualcaster Mage in hand
• available

Steps

1. Cast Demonic Gifts by paying its mana cost
2. Holding priority, cast Dualcaster Mage by paying its mana cost
3. When Dualcaster Mage enters, it triggers, copying Demonic Gifts, with the copy targeting Dualcaster Mage
4. Resolve the copy of Demonic Gifts
5. Holding priority, activate Phyrexian Altar by sacrificing Dualcaster Mage
6. When Dualcaster Mage dies, it triggers, returning it from your graveyard to the battlefield
7. Repeat from step 3

Results

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