Ashnod's Altar + Dualcaster Mage + Persist

Ashnod's Altar

Dualcaster Mage

Persist

How it works

1. Cast Persist by paying its mana cost, targeting any applicable target.
2. Holding priority, cast Dualcaster Mage by paying its mana cost.
3. When Dualcaster Mage enters, it triggers, targeting Persist.
4. Holding priority, activate Ashnod's Altar by sacrificing Dualcaster Mage.
5. Resolve the Dualcaster Mage trigger, copying Persist, with the copy targeting Dualcaster Mage
6. Resolve the Persist copy, returning Dualcaster Mage from your graveyard to the battlefield.
7. Repeat from step 3.

This clever loop sets up an infinite engine by leveraging Dualcaster Mage's enter-the-battlefield trigger to continuously copy Persist, which pulls the Mage right back out of the graveyard. Because Persist attaches a -1/-1 counter to the returned creature, you cannot loop the Mage forever via standard dying alone, but Ashnod's Altar neatly bypasses this restriction by sacrificing Dualcaster Mage on demand to feed the graveyard while generating a steady stream of colorless mana. Every single cycle yields fresh enters-the-battlefield and sacrifice triggers, turning this trio into a relentless engine of infinite resources.