Rings of Brighthearth, Seeker of Skybreak, and Incubation Druid

Prerequisites

• Rings of Brighthearth on the battlefield
• Seeker of Skybreak on the battlefield
• Incubation Druid on the battlefield
• Seeker of Skybreak and Incubation Druid do not have summoning sickness
• Incubation Druid has at least one +1/+1 counter on it

Steps

1. Activate Incubation Druid by tapping it, adding three mana of any color a land you control could produce
2. Activate Seeker of Skybreak by tapping it, targeting itself
3. Rings of Brighthearth triggers, causing you to pay to copy Seeker of Skybreak's ability, targeting Incubation Druid
4. Resolve both Seeker of Skybreak abilities, untapping it and Incubation Druid
5. Repeat

Results

• Infinite mana creatures you control can produce
• Infinite mana lands you control can produce
• Infinite untap of creatures you control