Trapjaw Kelpie + Bartolomé del Presidio + Hardened Academic

Trapjaw Kelpie

Bartolomé del Presidio

Hardened Academic

How it works

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

This loop relies on a clever interplay between the sacrifice outlet and graveyard-recycling mechanics. When you sacrifice Trapjaw Kelpie to Bartolomé del Presidio, persist brings it right back to the battlefield with a -1/-1 counter, but Hardened Academic steps in to counteract this drawback by placing a +1/+1 counter on the Kelpie whenever it leaves the graveyard. Because state-based actions immediately cause matching +1/+1 and -1/+1 counters to annihilate each other, Trapjaw Kelpie is left completely clean of counters and ready to be sacrificed all over again.