Sidisi, Regent of the Mire, Karmic Guide, Altar of Dementia, and Breaching Hippocamp

Prerequisites

• Sidisi, Regent of the Mire on the battlefield
• Karmic Guide in the graveyard
• Altar of Dementia on the battlefield
• Breaching Hippocamp on the battlefield

Steps

1. Activate Sidisi by tapping it and sacrificing Breaching Hippocamp, returning Karmic Guide from your graveyard to the battlefield
2. When Karmic Guide enters the battlefield, it triggers, returning Breaching Hippocamp from your graveyard to the battlefield
3. When Breaching Hippocamp enters the battlefield, it triggers, untapping Sidisi
4. Activate Altar of Dementia by sacrificing Karmic Guide
5. Repeat

Results

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