Workhorse, Mikaeus, the Unhallowed, and Altar of Dementia

Prerequisites

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

Steps

1. Activate Workhorse by removing all +1/+1 counters, adding that many
2. Activate Altar of Dementia by sacrificing Workhorse
3. Workhorse undying ability triggers, returning it to the battlefield with an additional +1/+1 counter on it
4. Resolve the Altar of Dementia ability, causing target player to mill one card
5. Repeat

Results

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