Carrion Feeder, Safehold Elite, and Hardened Academic

Prerequisites

• Carrion Feeder on the battlefield
• Safehold Elite on the battlefield
• Hardened Academic on the battlefield

Steps

1. Activate Carrion Feeder by sacrificing Safehold Elite
2. When Safehold Elite 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 Safehold Elite
4. Resolve the Carrion Feeder ability
5. Repeat

Results

• Infinite +1/+1 counters on a creature
• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers