Altar of Dementia + Thran Vigil + Rendclaw Trow

Altar of Dementia

Thran Vigil

Rendclaw Trow

How it works

1. Activate Altar of Dementia by sacrificing Rendclaw Trow.
2. When Rendclaw Trow 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 Rendclaw Trow.
4. Resolve the Altar of Dementia ability.
5. Repeat.

This clever loop uses Altar of Dementia to mill your opponents by repeatedly sacrificing Rendclaw Trow. Because Rendclaw Trow has persist, it returns to the battlefield after dying, but normally the `-1/-1` counter it enters with would prevent it from persisting a second time. That is where Thran Vigil comes in: every time the Trow leaves your graveyard to return to the field, Thran Vigil triggers to place a `+1/+1` counter on it, which immediately neutralizes the `-1/-1` counter through state-based actions. This resets the creature's persist ability entirely, allowing you to feed it back into the Altar indefinitely.