Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Geralf's Mindcrusher + Phyrexian Altar

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

Geralf's Mindcrusher

Phyrexian Altar

How it works

1. Activate Phyrexian Altar by sacrificing Geralf's Mindcrusher
2. When Geralf's Mindcrusher dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
3. When Geralf's Mindcrusher enters, it triggers, causing a player to mill five cards.
4. Activate Phyrexian Altar by sacrificing Geralf's Mindcrusher
5. When Geralf's Mindcrusher dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
6. When Geralf's Mindcrusher enters, it triggers, causing a player to mill five cards.
7. Repeat.

This clever loop relies on toggling the back-and-forth transformations of Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight to keep your graveyard recursion engine fully operational. While Eirdu's front face grants your creature spells convoke, its Isilu back face bestows persist onto your other nontoken creatures, perfectly complementing Geralf's Mindcrusher and its native undying ability. By repeatedly sacrificing Geralf's Mindcrusher to Phyrexian Altar, its counters alternate between +1/+1 and -1/+1 (effectively neutralizing one another each time it dies and returns), generating an endless supply of colored mana, death triggers, and player-milling goodness.