Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Melira's Keepers + Phyrexian Altar

Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight

Melira's Keepers

Phyrexian Altar

How it works

1. Activate Phyrexian Altar by sacrificing Melira's Keepers
2. When Melira's Keepers dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to its static effect.
3. Repeat.

This elegant loop sets up an infinite mana engine by exploiting a clever loophole in how counters interact with the battlefield. When you sacrifice Melira's Keepers to Phyrexian Altar, its persist ability triggers, but the Keepers's static ability prevents the -1/-1 counter from ever being placed upon its return. This allows you to sacrifice the creature to the Altar over and over again for an endless supply of any colored mana. Meanwhile, the front face, Eirdu, Carrier of Dawn, and its back face, Isilu, Carrier of Twilight, sit safely on the battlefield—while their presence isn't strictly required to execute the core loop, they provide a resilient life-gaining and spell-convoking foundation for your strategy before you initiate the sacrifice sequence.