Patron of the Moon, Azorius Chancery, and Horizon Explorer

Prerequisites

• Patron of the Moon on the battlefield
• Azorius Chancery in hand
• Horizon Explorer on the battlefield
• available

Steps

1. Pay to activate Patron of the Moon, putting Azorius Chancery from your hand onto the battlefield untapped due to Horizon Explorer
2. When Azorius Chancery enters, it triggers
3. Activate Azorius Chancery by tapping it, adding two mana
4. Resolve Azorius Chancery's triggered ability, returning it from the battlefield to your hand
5. Repeat

Results

• Infinite blue mana
• Infinite landfall triggers
• Infinite white mana