Stalwart Successor + Bartolomé del Presidio + Persistent Constrictor

Stalwart Successor

Bartolomé del Presidio

Persistent Constrictor

How it works

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

This clever loop hinges on the elegant interaction between Persistent Constrictor and Stalwart Successor: when the Constrictor returns via persist with a -1/-1 counter, the Successor's triggered ability steps in to place a +1/+1 counter on it for the first counters put on it that turn, which instantly neutralizes the -1/-1 counter. You can repeat this process indefinitely by feeding Persistent Constrictor to Bartolomé del Presidio, sacrificing it to constantly churn through its persist ability. Because every iteration resets the Constrictor's counters and triggers its return, Bartolomé del Presidio grows infinitely large while generating an endless stream of sacrifice, enter-the-battlefield, and leave-the-battlefield triggers.