Reveillark + Body Double + Ashnod's Altar

Reveillark

Body Double

Ashnod's Altar

How it works

1. Activate Ashnod's Altar by sacrificing Body Double, adding CC.
2. When Body Double leaves the battlefield, it triggers its Reveillark ability, returning itself from your graveyard to the battlefield as a copy of Reveillark.
3. Repeat.

This classic loop uses Ashnod's Altar as the engine to repeatedly sacrifice Body Double, which enters the battlefield copying Reveillark due to its own replacement effect. Because Body Double is currently a Reveillark, its departure from the battlefield triggers its copied leaves-the-battlefield ability, allowing it to pull itself right back out of the graveyard to do it all over again. Each iteration of this sacrifice cycle generates a surplus of colorless mana from the Altar while creating an infinite stream of creature entry, death, and sacrifice triggers to fuel your victory.