Reyhan, Last of the Abzan, Evolution Witness, and Phyrexian Altar

Prerequisites

• Reyhan, Last of the Abzan on the battlefield
• Evolution Witness on the battlefield
• Phyrexian Altar on the battlefield
• You have enough mana to cast the creature with MV<=1 if it doesn't have in its mana cost, or available otherwise

Steps

1. Cast the creature with MV<=1 by paying its mana cost if it doesn't have in its mana cost, or by paying otherwise, causing the creature to enter the battlefield with a +1/+1 counter on it
2. Activate Phyrexian Altar by sacrificing the creature, adding
3. When the creature dies, Reyhan triggers, putting a +1/+1 counter on Evolution Witness
4. Evolution Witness triggers, returning the creature from your graveyard to your hand
5. Repeat

Results

• Infinite +1/+1 counters on Evolution Witness
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers
• Infinite storm count