Agatha's Soul Cauldron + Aggravated Assault + Crystalline Crawler + Hakbal of the Surging Soul

GUR identity

Commander legal

The 4 combo pieces

What must be in place

You control at least five Merfolk.
You have a nonland card on top of your library.

How to execute it

  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. Move to your postcombat main phase.
  3. Activate five Merfolk you control using Crystalline Crawler's first ability by removing a +1/+1 counter from each of them, adding {3}{R}{R}.
  4. Activate Aggravated Assault by paying {3}{R}{R}, causing you to untap all creatures you control and to get an additional combat phase after this one.
  5. Repeat.
  6. If you control six or more Merfolk, this combo nets infinite colored mana and +1/+1 counters on Merfolk you control.

What the combo produces