Surrak and Goreclaw + Lesser Masticore + Altar of Dementia

Surrak and Goreclaw

Lesser Masticore

Altar of Dementia

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 the battlefield, Surrak and Goreclaw triggers, putting a +1/+1 counter on Lesser Masticore and giving it haste until end of turn.
4. Resolve the Altar of Dementia ability from step 1, causing target player to mill cards equal to Lesser Masticore's power.
5. Repeat.