Dualcaster Mage + Persist + Yahenni, Undying Partisan

Dualcaster Mage

Persist

Yahenni, Undying Partisan

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 Yahenni 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 sacrifice engine by using Yahenni, Undying Partisan as a reliable outlet to feed our graveyard loops. When you cast Persist and follow it up with Dualcaster Mage, the Mage's enters-the-battlefield trigger targets the original spell on the stack. Before that copy resolves, Yahenni, Undying Partisan lets you sacrifice the Dualcaster Mage, sending it back to the graveyard just in time for the copied Persist to bring it right back to the battlefield with a -1/-1 counter. Because Dualcaster Mage triggers fresh upon its return to copy Persist once again, the process loops indefinitely to continuously sacrifice and recur your creatures.