Toph, the First Metalbender, Magus of the Candelabra, Thousand-Year Elixir, and Nyxbloom Ancient

Prerequisites

• Toph, the First Metalbender on the battlefield
• Magus of the Candelabra on the battlefield
• Thousand-Year Elixir on the battlefield
• Nyxbloom Ancient on the battlefield

Steps

1. Activate two lands by tapping them, adding at least due to Nyxbloom Ancient
2. Activate Magus of the Candelabra by paying and tapping it, untapping the two mana-producing lands and Thousand-Year Elixir, as it's a land due to Toph
3. Activate Thousand-Year Elixir by paying and tapping it, untapping Magus of the Candelabra
4. Repeat

Results

• Infinite mana lands you control can produce
• Infinite mana nontoken artifacts you control can produce
• Infinite untap of lands you control
• Infinite untap of nontoken artifacts you control