Reincarnation + Dualcaster Mage + Carrion Feeder

Reincarnation

Dualcaster Mage

Carrion Feeder

How it works

1. Cast Reincarnation by paying its mana cost.
2. Holding priority, cast Dualcaster Mage by paying its mana cost.
3. When Dualcaster Mage enters, it triggers, copying Reincarnation, with the copy targeting Dualcaster Mage.
4. Resolve the copy of Reincarnation.
5. Holding priority, activate Carrion Feeder by sacrificing Dualcaster Mage.
6. When Dualcaster Mage dies, Reincarnation triggers, returning Dualcaster Mage from your graveyard to the battlefield.
7. Repeat from step 3.
8. Resolve all Carrion Feeder abilities from step 5.

This brilliant loop sets up an endless cycle of sacrifice and resurrection by turning Dualcaster Mage into its own catalyst. When you cast Reincarnation and respond with Dualcaster Mage, the Mage's enters-the-battlefield ability copies the spell to target the Mage itself, priming the loop for execution. From there, you simply sacrifice the Mage to Carrion Feeder's activated ability, which immediately triggers the original Reincarnation waiting in the graveyard to pull the Mage right back onto the battlefield. Because Dualcaster Mage triggers anew every single time it returns, you can continuously copy Reincarnation, sacrificing the Mage over and over to feed Carrion Feeder infinite +1/+1 counters while generating endless death and enter-the-battlefield triggers.