Cass, Hand of Vengeance, Ashnod's Altar, and Siona, Captain of the Pyleas

Prerequisites

• Cass, Hand of Vengeance on the battlefield
• Ashnod's Altar on the battlefield
• Siona, Captain of the Pyleas on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing another creature that has an Aura attached to it
2. When the creature dies, Cass triggers, returning an Aura that was attached to the creature from your graveyard to the battlefield attached to another creature you control
3. When the Aura enters the battlefield, Siona triggers, creating a creature token
4. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite colorless mana
• Infinite death triggers
• Infinite sacrifice triggers