Stalwart Successor + Altar of Dementia + Lesser Masticore

Stalwart Successor

Altar of Dementia

Lesser Masticore

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, Stalwart Successor triggers, putting a +1/+1 counter on Lesser Masticore
4. Resolve the Altar of Dementia ability.
5. Repeat.

This clever loop exploits a clever counter-canceling interaction to grind through an opponent's library. Whenever Lesser Masticore dies, its persist ability normally brings it back with a -1/-1 counter, but Stalwart Successor steps in to save the day by placing a +1/+1 counter on it instead, neutralizing the -1/-1 counter via state-based actions and leaving the Masticore pristine for the next cycle. You can then feed that endless resurrection directly into Altar of Dementia, turning the perpetual sacrifice loop into an endless mill that tears through your opponents' libraries in a single turn.