Safehold Elite, Yahenni, Undying Partisan, and Hardened Academic

Prerequisites

• Safehold Elite on the battlefield
• Yahenni, Undying Partisan on the battlefield
• Hardened Academic on the battlefield

Steps

1. Activate Yahenni 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 Yahenni ability
5. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers