Berta, Wise Extrapolator + Intruder Alarm + Ivy Lane Denizen

Berta, Wise Extrapolator

Intruder Alarm

Ivy Lane Denizen

How it works

1. Activate Berta by paying 1 and tapping it, creating a 0/0 Fractal creature token and putting a +1/+1 counter on it.
2. When the Fractal enters, Intruder Alarm and Ivy Lane Denizen trigger.
3. Resolve the Intruder Alarm trigger, untapping all creatures.
4. Resolve the Ivy Lane Denizen trigger, putting a +1/+1 counter on Berta.
5. Berta triggers, adding 1.
6. Repeat.

This loop transforms a modest investment of mana into an overwhelming cascade by setting up a self-sustaining cycle of creature growth and untapping. You begin by paying into Berta, Wise Extrapolator's activated ability, churning out a green and blue Fractal creature token that immediately triggers Ivy Lane Denizen to place a +1/+1 counter back onto Berta. That counter generation forces Berta to refund your mana, while Intruder Alarm ensures your entire board—including Berta—untaps fresh and ready every single time a new token arrives.