Yarok, the Desecrated + Soul Foundry + Corridor Monitor + Gilded Lotus

Yarok, the Desecrated

Soul Foundry

Corridor Monitor

Gilded Lotus

How it works

1. Activate Gilded Lotus by tapping it, adding three mana of any color.
2. Activate Soul Foundry by paying 2 and tapping it, creating a token copy of Corridor Monitor.
3. When the Corridor Monitor token enters the battlefield, it triggers twice, untapping Soul Foundry and Gilded Lotus.
4. Repeat.

This engine relies on the multiplicative power of Yarok, the Desecrated to turn a simple copy loop into an overwhelming cascade of value. You use Soul Foundry to repeatedly deploy Corridor Monitor, whose entry triggers are doubled by Yarok to effortlessly untap both the Foundry and your Gilded Lotus. This leaves you with a surplus of mana at every iteration, letting you generate infinite colored mana, infinite tokens, and an endlessly repeating cycle of enters-the-battlefield triggers.