Altar of Dementia + Lesser Masticore + Mm'menon, Uthros Exile

Altar of Dementia

Lesser Masticore

Mm'menon, Uthros Exile

How it works

1. Activate Altar of Dementia by sacrificing Lesser Masticore.
2. When Lesser Masticore dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When Lesser Masticore enters, Mm'menon triggers, putting a +1/+1 counter on Lesser Masticore.
4. Resolve the Altar of Dementia ability.
5. Repeat.

This ingenious loop transforms Lesser Masticore into a self-sustaining sacrifice engine by taking advantage of the creature's persist ability to bring it right back from the dead. Whenever Lesser Masticore re-enters the battlefield with a pesky -1/-1 counter, Mm'menon, Uthros Exile steps in with its triggered ability to immediately place a +1/+1 counter on it, which neatly cancels out the minus counter due to state-based actions. With the slate wiped clean each cycle, you can feed Lesser Masticore back into Altar of Dementia over and over again to grind through your opponent's library with infinite mill.