Ertha Jo, Frontier Mentor, Staff of Domination, and Gumato

Prerequisites

• Ertha Jo, Frontier Mentor on the battlefield
• Staff of Domination on the battlefield
• Gumato on the battlefield
• available

Steps

1. Activate Staff of Domination's third ability by paying , targeting Gumato
2. Ertha Jo triggers, copying Staff of Domination's ability, targeting Gumato
3. Resolve the first Staff of Domination ability, untapping Gumato
4. Holding priority, activate Gumato by tapping it, adding Resolve the second Staff of Domination ability, untapping Gumato
5. Activate Gumato by tapping it, adding Activate Staff of Domination's first ability by paying , untapping it
6. Repeat

Results

• Infinite card draw
• Infinite draw triggers
• Infinite green mana
• Infinite lifegain
• Infinite lifegain triggers
• Infinite mana creatures you control can produce
• Infinite untap of creatures you control