Phyrexian Altar + Dualcaster Mage + Abnormal Endurance

Phyrexian Altar

Dualcaster Mage

Abnormal Endurance

How it works

1. Cast Abnormal Endurance by paying its mana cost.
2. Holding priority, cast Dualcaster Mage by paying its mana cost.
3. When Dualcaster Mage enters, it triggers, copying Abnormal Endurance, with the copy targeting Dualcaster Mage.
4. Resolve the copy of Abnormal Endurance.
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.

This clever loop transforms a simple pump spell into a self-sustaining engine by orchestrating a recursive dance around the stack. When you cast Abnormal Endurance and follow it with Dualcaster Mage, the Mage's enters-the-battlefield ability copies the endurance spell right back onto itself. Once that protective effect resolves, Phyrexian Altar steps in to harvest the mage for mana, triggering the delayed return clause that puts Dualcaster Mage right back onto the battlefield to copy the endurance spell all over again.