Reveillark, Activated Sleeper, and Ashnod's Altar

Prerequisites

• Reveillark on the battlefield
• Activated Sleeper in the graveyard
• Ashnod's Altar on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Reveillark, adding
2. When Reveillark dies, it triggers, returning Activated Sleeper from your graveyard to the battlefield as a copy of Reveillark
3. Activate Ashnod's Altar by sacrificing Activated Sleeper, adding
4. When Activated Sleeper dies, it triggers, returning Activated Sleeper from your graveyard to the battlefield as a copy of Reveillark
5. Repeat from step 3

Results

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