Ashnod's Altar + Dualcaster Mage + Faith's Reward

Ashnod's Altar

Dualcaster Mage

Faith's Reward

How it works

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

This clever loop relies on Dualcaster Mage’s enter-the-battlefield ability to endlessly copy the spell that brought it back, Faith's Reward. By sacrificing Dualcaster Mage to Ashnod's Altar in response to its own copy trigger, you generate a surplus of colorless mana while sending the Mage safely to the graveyard. Faith's Reward then returns Dualcaster Mage to the battlefield, ready to target the original spell (or another copy of it) all over again, fueling an infinite engine of death triggers and massive mana.