Ashnod's Altar, and First Day of Class

Prerequisites

• Ashnod's Altar on the battlefield
• First Day of Class in hand
• available

Steps

1. Cast First Day of Class by paying
2. Activate Ashnod's Altar by sacrificing the persist creature
3. When the persist creature dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
4. When the persist creature enters, First Day of Class triggers, putting a +1/+1 counter on the persist creature
5. Repeat from step 2

Results

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