Thermopod + Lesser Masticore + Sigil Captain

Thermopod

Lesser Masticore

Sigil Captain

How it works

1. Activate Thermopod by sacrificing Lesser Masticore
2. When Lesser Masticore dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When Lesser Masticore enters, Sigil Captain triggers, putting a +1/+1 counter on Lesser Masticore
4. Repeat.

This brilliant loop centers on Lesser Masticore entering the battlefield as a 1/1, which immediately catches the attention of Sigil Captain to place two +1/+1 counters on it. Because the -1/-1 counter from persist and the new +1/+1 counters annihilate each other through state-based actions, Lesser Masticore is left completely clean of counters and ready to die all over again. You simply feed it to Thermopod's sacrifice ability to generate a steady stream of red mana while simultaneously resetting the whole cycle.