Rings of Brighthearth, Seeker of Skybreak, and Circle of Dreams Druid

Prerequisites

• Rings of Brighthearth on the battlefield
• Seeker of Skybreak on the battlefield
• Circle of Dreams Druid on the battlefield
• Seeker of Skybreak and Circle of Dreams Druid do not have summoning sickness
• You control at least three creatures

Steps

1. Activate Circle of Dreams Druid by tapping it, adding at least
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 Circle of Dreams Druid
4. Resolve both Seeker of Skybreak abilities, untapping it and Circle of Dreams Druid
5. Repeat

Results

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