Mikaeus, the Unhallowed, Altar of Dementia, and Tatterkite

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Altar of Dementia on the battlefield
• Tatterkite on the battlefield

Steps

1. Activate Altar of Dementia by sacrificing Tatterkite
2. When Tatterkite dies, its undying ability triggers, returning it to the battlefield from your graveyard with zero +1/+1 counters due to its ability
3. Resolve the Altar of Dementia ability from step 1, causing target player to mill cards equal to Tatterkite's power
4. Repeat

Results

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