Berta, Wise Extrapolator + Animation Module + Agatha's Soul Cauldron + Carrion Feeder

Berta, Wise Extrapolator

Animation Module

Agatha's Soul Cauldron

Carrion Feeder

How it works

1. Activate Berta using Carrion Feeder's ability by sacrificing a creature, putting a +1/+1 counter on Berta.
2. Berta and Animation Module trigger.
3. Resolve the Berta trigger, adding 1.
4. Resolve the Animation Module trigger, causing you to pay 1 to create a 1/1 Servo artifact creature token.
5. Repeat

This clever engine leverages Berta, Wise Extrapolator as a mana-positive engine by activating her token-making ability using Carrion Feeder to sacrifice the resulting tokens, which simultaneously grows your board and fuels her counters. Animation Module acts as the crucial recursive multiplier here, turning every single +1/+1 counter placed on Berta into a fresh Servo token for just one mana, keeping your sacrifice fodder perpetually replenished. Meanwhile, Agatha's Soul Cauldron quietly supports the strategy by allowing you to spend mana of any color and potentially borrow exiled utility, ensuring the loop runs seamlessly without ever stalling out on resources.