Mikaeus, the Unhallowed, Altar of Dementia, and Dread Tiller

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Altar of Dementia on the battlefield
• Dread Tiller on the battlefield

Steps

1. Activate Altar of Dementia by sacrificing Dread Tiller
2. When Dread Tiller dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
3. When Dread Tiller enters the battlefield, it triggers, putting a -1/-1 counter on it
4. Resolve the Altar of Dementia ability Repeat

Results

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