Rings of Brighthearth, Seeker of Skybreak, and Sanctum Weaver

Prerequisites

• Rings of Brighthearth on the battlefield
• Seeker of Skybreak on the battlefield
• Sanctum Weaver on the battlefield
• Seeker of Skybreak and Sanctum Weaver do not have summoning sickness
• You control at least three enchantments

Steps

1. Activate Sanctum Weaver by tapping it, adding at least three mana of any color
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 Sanctum Weaver
4. Resolve both Seeker of Skybreak abilities, untapping it and Sanctum Weaver
5. Repeat

Results

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