Restless Apparition + Thran Vigil + Bloodflow Connoisseur

Restless Apparition

Thran Vigil

Bloodflow Connoisseur

How it works

1. Activate Bloodflow Connoisseur by sacrificing Restless Apparition.
2. When Restless Apparition 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 Restless Apparition.
4. Resolve the Bloodflow Connoisseur ability.
5. Repeat.

This loop creates an infinite engine by leveraging Restless Apparition's persist ability alongside the sacrifice outlet provided by Bloodflow Connoisseur. Whenever Restless Apparition dies, it returns to the battlefield with a -1/-1 counter, but Thran Vigil cleverly intervenes by placing a +1/+1 counter on it the moment it leaves the graveyard. Since Magic's state-based actions cause +1/+1 and -1/+1 counters to annihilate each other in pairs, the creature enters its next cycle clean of counters and ready to be sacrificed all over again.