Ray Fillet, Man Ray + Berta, Wise Extrapolator + Heartstone + Lyla, Holographic Assistant

Ray Fillet, Man Ray

Berta, Wise Extrapolator

Heartstone

Lyla, Holographic Assistant

How it works

1. Activate Ray Fillet by paying 1 due to Heartstone and removing a +1/+1 counter from a creature you control, causing you to draw a card.
2. Lyla triggers, putting a +1/+1 counter on Berta.
3. Berta triggers, adding 1.
4. Repeat.

This clever engine starts by using Ray Fillet, Man Ray's activated ability to draw a card, with its cost neatly reduced to just one mana thanks to Heartstone. Because you're drawing a card, Lyla, Holographic Assistant triggers to place a +1/+1 counter onto Berta, Wise Extrapolator. That influx of counters causes Berta to trigger in turn, generating the exact mana needed to pay for Ray Fillet's ability again and keep the loop spinning infinitely.