Hakbal of the Surging Soul, Agatha's Soul Cauldron, Crystalline Crawler, and Hellkite Charger

Prerequisites

• Hakbal of the Surging Soul on the battlefield
• Agatha's Soul Cauldron on the battlefield
• Crystalline Crawler in exile
• Hellkite Charger on the battlefield
• You control at least seven Merfolk
• You have a nonland card on top of your library
• An opponent cannot block and kill Hellkite Charger

Steps

1. At the beginning of your combat phase, Hakbal of the Surging Soul's first ability triggers, causing you to reveal the top card of your library, put a +1/+1 counter on each Merfolk you control and putting the card back on top of your library
2. Declare Hellkite Charger as an attacker, triggering its ability
3. Activate seven Merfolk you control using Crystalline Crawler's first ability by removing a +1/+1 counter from each of them, adding
4. Resolve the Hellkite Charger trigger, causing you to pay to untap all attacking creatures you control and to get an additional combat phase after this one
5. Repeat each combat phase
6. If you control eight or more Merfolk, this combo nets infinite colored mana and +1/+1 counters on Merfolk you control

Results

• Infinite +1/+1 counters on each Merfolk you control
• Infinite colored mana
• Infinite combat phases