Athreos, Shroud-Veiled, Blue, Loyal Raptor, and Altar of Dementia

Prerequisites

• Athreos, Shroud-Veiled on the battlefield
• Blue, Loyal Raptor on the battlefield
• Altar of Dementia on the battlefield

Steps

1. Cast the Dinosaur in your hand by paying its mana cost
2. It will enter with a coin counter due to Blue
3. Activate Altar of Dementia by sacrificing the Dinosaur
4. When the Dinosaur dies, Athreos's second ability triggers, returning the Dinosaur from your graveyard to the battlefield
5. It will enter with a coin counter due to Blue
6. Resolve the Altar of Dementia ability
7. Repeat from step 2

Results

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