Altar of Dementia + Twilight Shepherd + Thran Vigil

Altar of Dementia

Twilight Shepherd

Thran Vigil

How it works

1. Activate Altar of Dementia by sacrificing Twilight Shepherd.
2. When Twilight Shepherd dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Thran Vigil triggers, putting a +1/+1 counter on Twilight Shepherd.
4. Resolve the Altar of Dementia ability.
5. Repeat.

This ingenious loop relies on Twilight Shepherd as both the engine and the recurring sacrifice, using Altar of Dementia to mill your opponents out in the process. Each time Twilight Shepherd is sacrificed, its persist ability brings it back with a -1/-1 counter, but Thran Vigil brilliantly neutralizes this drawback during your turn by placing a +1/+1 counter on it whenever it leaves the graveyard. These two opposing counters instantly annihilate each other through state-based actions, resetting Twilight Shepherd's persist eligibility so the entire cycle can repeat endlessly.