Crystalline Crawler, Evolution Witness, Cathars' Crusade, and Viscera Seer

Prerequisites

• Crystalline Crawler on the battlefield
• Evolution Witness on the battlefield
• Cathars' Crusade on the battlefield
• Viscera Seer on the battlefield

Steps

1. Cast the creature with mana value 1 or less from your hand by paying its mana cost
2. When the creature enters, Cathars' Crusade triggers
3. Holding priority, activate Viscera Seer by sacrificing the creature
4. Resolve the Cathars' Crusade trigger, putting a +1/+1 counter on each creature you control
5. Evolution Witness triggers, returning the creature with mana value 1 or less from your graveyard to your hand
6. Activate Crystalline Crawler by removing a +1/+1 counter from it, adding one mana of any color
7. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite scry 1
• Infinite storm count
• Infinite +1/+1 counters