Boonweaver Giant, Unhallowed Pact, and Yahenni, Undying Partisan

Prerequisites

• Boonweaver Giant on the battlefield
• Unhallowed Pact on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Yahenni by sacrificing Boonweaver Giant When Boonweaver Giant dies, Unhallowed Pact triggers, returning Boonweaver Giant from your graveyard to the battlefield When Boonweaver Giant enters, it triggers, returning Unhallowed Pact from your graveyard to the battlefield attached to Boonweaver Giant
2. Resolve the Yahenni ability from step 1
3. Repeat

Results

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