Reaping Willow, Phyrexian Altar, Agatha of the Vile Cauldron, and Chaos Spewer

Prerequisites

• Reaping Willow on the battlefield
• Phyrexian Altar on the battlefield
• Agatha of the Vile Cauldron on the battlefield
• Chaos Spewer in the graveyard
• available

Steps

1. Activate Reaping Willow by paying due to Agatha of the Vile Cauldron and removing two counters from it, returning Chaos Spewer from your graveyard to the battlefield
2. When Chaos Spewer enters, it triggers, putting two -1/-1 counters on Reaping Willow
3. Activate Phyrexian Altar by sacrificing Chaos Spewer, adding
4. Repeat

Results

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