Patron of the Moon + Spelunking + Arid Archway

Patron of the Moon

Spelunking

Arid Archway

How it works

1. Activate Patron of the Moon by paying 1, putting Arid Archway from your hand onto the battlefield untapped due to Spelunking.
2. When Arid Archway enters the battlefield, it triggers.
3. Holding priority, activate Arid Archway by tapping it, adding CC.
4. Resolve the Arid Archway trigger from step 2, returning it from the battlefield to your hand.
5. Repeat.

This loop transforms Patron of the Moon's land-dropping ability into a perpetual engine by leveraging Spelunking's static ability, which ensures lands enter the battlefield completely untapped. When you use Patron of the Moon to drop Arid Archway, the land's own entering trigger forces it right back to your hand, but because Arid Archway taps for two colorless mana ({C}{C}), you easily profit enough mana to fund the entire loop while generating infinite colorless mana, landfall triggers, and repeatable resources.