Stalwart Successor + Viscera Seer + Kithkin Spellduster

Stalwart Successor

Viscera Seer

Kithkin Spellduster

How it works

1. Activate Viscera Seer by sacrificing Kithkin Spellduster
2. When Kithkin Spellduster dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When Kithkin Spellduster enters, Stalwart Successor triggers, putting a +1/+1 counter on Kithkin Spellduster
4. Resolve the Viscera Seer ability.
5. Repeat.

This clever loop turns Kithkin Spellduster into an immortal sacrifice engine by exploiting the interaction between persist and counter-placement. When you sacrifice the Spellduster to Viscera Seer, persist returns it with a -1/-1 counter, but Stalwart Successor immediately steps in to trigger on those new counters, placing a +1/+1 counter on the bird-kithkin. Because state-based actions automatically annihilate opposing +1/+1 and -1/+1 counters in a mutually destructive puff of rules text, the Spellduster is left completely clean of counters and ready to die all over again.