Ultros, Obnoxious Octopus, Agatha's Soul Cauldron, Crystalline Crawler, and Wurmcalling

Prerequisites

• Ultros, Obnoxious Octopus on the battlefield
• Agatha's Soul Cauldron on the battlefield
• Crystalline Crawler in exile
• Wurmcalling in hand
• available

Steps

1. Cast Wurmcalling with buyback by paying
2. Ultros's first and second abilities trigger, tapping a creature an opponent controls and putting a stun counter on it, and then putting eight +1/+1 counters on Ultros
3. Resolve Wurmcalling, creating a 4/4 Wurm creature token and returning Wurmcalling to your hand
4. Activate Ultros using Crystalline Crawler's first ability eight times by removing eight +1/+1 counter from it, adding
5. Repeat

Results

• Infinite ETB
• Infinite storm count
• Infinite creature tokens
• Infinite magecraft triggers