Agatha's Soul Cauldron + Kiki-Jiki, Mirror Breaker + Renata, Called to the Hunt

Agatha's Soul Cauldron

Kiki-Jiki, Mirror Breaker

Renata, Called to the Hunt

How it works

1. Activate a creature you control with a +1/+1 counter on it using Kiki-Jiki's ability by tapping it, creating a token copy of any nonlegendary creature you control with haste that enters the battlefield with a +1/+1 counter on it due to Renata.
2. Repeat.

This loop relies on Agatha's Soul Cauldron to grant Kiki-Jiki, Mirror Breaker's activated ability to a creature equipped with a +1/+1 counter. Renata, Called to the Hunt ensures this process is self-sustaining by automatically placing an additional +1/+1 counter on the token copy as it enters the battlefield, immediately giving the new token the ability to tap and create yet another copy. Because Agatha's Soul Cauldron also lets you spend mana as though it were mana of any color, the engine runs smoothly while churning out an endless army of hasty tokens.