Lesser Masticore, Thran Vigil, and Yahenni, Undying Partisan

Prerequisites

• Lesser Masticore on the battlefield
• Thran Vigil on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Yahenni 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. Thran Vigil triggers, putting a +1/+1 counter on Lesser Masticore
4. Resolve the Yahenni ability
5. Repeat

Results

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