Reaping Willow, Ashnod's Altar, Agatha's Soul Cauldron, and Plague Belcher

Prerequisites

• Reaping Willow on the battlefield
• Ashnod's Altar on the battlefield
• Agatha's Soul Cauldron on the battlefield
• Plague Belcher in the graveyard
• available

Steps

1. Activate Reaping Willow by paying due to Agatha's Soul Cauldron and removing two counters from it, returning Plague Belcher from your graveyard to the battlefield
2. When Plague Belcher enters, it triggers, putting two -1/-1 counters on Reaping Willow
3. Activate Ashnod's Altar by sacrificing Plague Belcher, adding
4. Repeat

Results

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