Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Luminous Broodmoth + Altar of Dementia

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

Luminous Broodmoth

Altar of Dementia

How it works

1. Activate Altar of Dementia by sacrificing another nontoken creature that doesn't have flying.
2. When the creature dies, Luminous Broodmoth triggers, returning the creature from your graveyard to the battlefield with a flying counter on it.
3. Activate Altar of Dementia by sacrificing the creature with a flying counter on it.
4. When the creature dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
5. Resolve the Altar of Dementia abilities from step 1 and 3.
6. Repeat.

This clever loop exploits a clever layering of replacement effects to endlessly recycle your creatures right into Altar of Dementia. While Isilu, Carrier of Twilight (the back face of Eirdu, Carrier of Dawn) grants your other nontoken creatures persist to bring them back after dying with a -1/-1 counter, Luminous Broodmoth catches those same creatures when they die *without* flying counters, returning them with a flying counter instead. Because these two return mechanisms alternate based on the counters currently on the creature, you can endlessly sacrifice it to mill your opponents' entire libraries.