Blossoming Tortoise + Deserted Temple + Rings of Brighthearth + Lotus Field

Blossoming Tortoise

Deserted Temple

Rings of Brighthearth

Lotus Field

How it works

1. Activate Lotus Field by tapping it, adding three mana of any color
2. Activate Deserted Temple's second ability by tapping it, targeting Lotus Field.
3. Rings of Brighthearth triggers, causing you to pay 2 to copy Deserted Temple's ability, targeting Deserted Temple.
4. Resolve both Deserted Temple abilities, untapping Deserted Temple and Lotus Field
5. Repeat

This elegant mana engine hinges on leveraging Deserted Temple to repeatedly untap Lotus Field, utilizing its massive three-mana production to fund the entire loop. To turn this simple pairing into an infinite supply of colored mana, Rings of Brighthearth steps in to duplicate the Temple's untap ability, allowing you to untap both the Temple and the Lotus Field simultaneously. Meanwhile, Blossoming Tortoise plays a vital foundational role by reducing the activation cost of lands you control like Deserted Temple down to just a single mana, while also providing a steady stream of land recursion and a passive buff to any land creatures.