Priest of Titania, Rings of Brighthearth, and Aphetto Alchemist

Prerequisites

• Priest of Titania on the battlefield
• Rings of Brighthearth on the battlefield
• Aphetto Alchemist on the battlefield
• Priest of Titania and Aphetto Alchemist do not have summoning sickness
• There are at least three Elves on the battlefield

Steps

1. Activate Priest of Titania by tapping it, adding at least
2. Activate Aphetto Alchemist by tapping it, targeting itself
3. Rings of Brighthearth triggers, causing you to pay to copy Aphetto Alchemist's ability, targeting Priest of Titania
4. Resolve both Aphetto Alchemist abilities, untapping it and Priest of Titania
5. Repeat

Results

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