Ioreth of the Healing House, Aura of Dominion, and Vhal, Candlekeep Researcher

Prerequisites

• Ioreth of the Healing House on the battlefield
• Aura of Dominion on the battlefield
• Vhal, Candlekeep Researcher on the battlefield

Steps

1. Activate Vhal by tapping it, adding at least that cannot be spent to cast spells from your hand
2. Activate Ioreth's second ability by tapping it, untapping Vhal and another legendary creature
3. Activate Aura of Dominion by paying and tapping the other legendary creature, untapping Ioreth
4. Repeat

Results

• Infinite mana legendary creatures you control can produce
• Infinite untap of legendary creatures you control
• Infinite colorless mana that can't be spent to cast spells from your hand