Gerrard, Weatherlight Hero, Loyal Retainers, and Altar of Dementia

Prerequisites

• Gerrard, Weatherlight Hero on the battlefield
• Loyal Retainers on the battlefield
• Altar of Dementia on the battlefield
• It is your precombat main phase

Steps

1. Activate Altar of Dementia by sacrificing Gerrard
2. Gerrard dies, triggering its ability
3. Holding priority, activate Loyal Retainers by sacrificing it, returning Gerrard from your graveyard to the battlefield
4. Resolve the Gerrard trigger, returning all artifact and creature cards put into your graveyard this turn to the battlefield
5. Resolve the Altar of Dementia ability from step 1, causing target player to mill cards equal to Gerrard's power
6. Repeat

Results

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