Iridescent Drake + Unhallowed Pact + Phyrexian Altar

Iridescent Drake

Unhallowed Pact

Phyrexian Altar

How it works

1. Activate Phyrexian Altar by sacrificing Iridescent Drake, adding one mana of any color.
2. When Iridescent Drake dies, Unhallowed Pact triggers, returning Iridescent Drake from your graveyard to the battlefield.
3. When Iridescent Drake enters the battlefield, it triggers, returning Unhallowed Pact from your graveyard to the battlefield attached to Iridescent Drake.
4. Repeat.

This elegant loop sets up a perpetual cycle of life and death, turning the sacrifice outlet into a limitless engine. Phyrexian Altar provides the crucial mana production whenever a creature meets its end, while Unhallowed Pact ensures that sacrifice doesn't stick by dragging its host right back from the graveyard. Finally, Iridescent Drake acts as the catalyst that reconnects the entire loop, fetching Unhallowed Pact out of the graveyard and attaching it the moment the Drake touches the battlefield once more.