Patron of the Moon, Guildless Commons, and Horizon Explorer

Prerequisites

• Patron of the Moon on the battlefield
• Guildless Commons in hand
• Horizon Explorer on the battlefield
• available

Steps

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

Results

• Infinite colorless mana
• Infinite landfall triggers