Ioreth of the Healing House, and Seeker of Skybreak

Prerequisites

• Ioreth of the Healing House on the battlefield
• Seeker of Skybreak on the battlefield
• Ioreth and Seeker of Skybreak do not have summoning sickness
• There is another legendary creature on the battlefield

Steps

1. If Seeker of Skybreak is not your Ring-bearer, use the card that causes the Ring to tempt you to cause Seeker of Skybreak to become your Ring-bearer, thus making it legendary
2. Activate Ioreth's second ability by tapping it, untapping Seeker of Skybreak and another legendary creature
3. Activate Seeker of Skybreak by tapping it, untapping Ioreth
4. Repeat from step 2

Results

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