Rings of Brighthearth + Seeker of Skybreak + Kami of Whispered Hopes

Rings of Brighthearth

Seeker of Skybreak

Kami of Whispered Hopes

How it works

1. Activate Kami of Whispered Hopes by tapping it, adding at least three mana of any color.
2. Activate Seeker of Skybreak by tapping it, targeting itself.
3. Rings of Brighthearth triggers, causing you to pay 2 to copy Seeker of Skybreak's ability, targeting Kami of Whispered Hopes.
4. Resolve both Seeker of Skybreak abilities, untapping it and Kami of Whispered Hopes.
5. Repeat.

This looping engine kicks off when Kami of Whispered Hopes taps for a massive influx of mana, its replacement effect supercharging its own power with extra +1/+1 counters to make that mana output even greater. With that mana fueling the engine, you activate Seeker of Skybreak to untap itself, while Rings of Brighthearth steps in to copy that untap ability so you can simultaneously refresh Kami of Whispered Hopes. Because Rings of Brighthearth lets you repeat this untap dance endlessly for just a couple of mana, you generate infinite untaps and infinite colored mana from your creatures.