Yedora, Grave Gardener, Ambush Commander, and Altar of Dementia

Prerequisites

• Yedora, Grave Gardener on the battlefield
• Ambush Commander on the battlefield
• Altar of Dementia on the battlefield
• You control at least one additional nontoken Forest

Steps

1. Activate Altar of Dementia by sacrificing a nontoken Forest, which is a creature due to Ambush Commander
2. When the Forest dies, Yedora triggers, returning the Forest from your graveyard to the battlefield face down as a Forest land
3. Resolve the Altar of Dementia ability, causing target player to mill cards equal to the sacrificed creature's power
4. Repeat

Results

• Infinite death triggers
• Infinite ETB
• Infinite landfall triggers
• Infinite LTB
• Infinite mill
• Infinite sacrifice triggers
• Infinite self-mill