Rings of Brighthearth + Deserted Temple + Matzalantli, the Great Door // The Core Combo

All permanents on the battlefield.

You have at least four permanent cards in your graveyard.

Activate The Core by tapping it, adding at least four mana of any color.

Activate Deserted Temple's second ability by paying and tapping it, targeting The Core.

Rings of Brighthearth triggers, causing you to pay to copy Deserted Temple's ability, targeting Deserted Temple.

Resolve both Deserted Temple abilities, untapping Deserted Temple and The Core

Repeat

Infinite colored mana

Infinite mana lands you control can produce

Infinite untap of lands you control