Sidisi, Regent of the Mire, Bladewing the Risen, Thornbite Staff, and Altar of Dementia

Prerequisites

• Sidisi, Regent of the Mire on the battlefield
• Bladewing the Risen in the graveyard
• Thornbite Staff on the battlefield
• Altar of Dementia on the battlefield

Steps

1. Activate Sidisi by tapping it and sacrificing a nontoken Dragon with mana value 6
2. When the creature dies, Sidisi triggers, untapping Sidisi
3. Resolve the Sidisi ability, returning Bladewing from your graveyard to the battlefield
4. When Bladewing enters the battlefield, it triggers, returning the Dragon with mana value 6 from your graveyard to the battlefield
5. Activate Altar of Dementia by sacrificing Bladewing
6. When Bladewing dies, Sidisi triggers, untapping Sidisi
7. Resolve the Altar of Dementia ability
8. Repeat

Results

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