Phyrexian Altar + Dualcaster Mage + Second Sunrise

Phyrexian Altar

Dualcaster Mage

Second Sunrise

How it works

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

This elegant loop achieves infinite colored mana and endless triggers by leveraging the recursive power of Second Sunrise to constantly pull your graveyard back to the battlefield. The engine relies on Dualcaster Mage entering the battlefield to copy that very spell on the stack, ensuring a fresh copy is always ready to resolve. Before the copy resolves, Phyrexian Altar is there to instantly sacrifice the Mage for mana, neatly sending it back to the graveyard just in time for Second Sunrise's effect to return it and start the cycle anew.