Thopter Squadron + Crystalline Crawler + Yarok, the Desecrated + Mm'menon, Uthros Exile

Thopter Squadron

Crystalline Crawler

Yarok, the Desecrated

Mm'menon, Uthros Exile

How it works

1. Activate Thopter Squadron's first ability by paying 1 and removing a +1/+1 counter from it, creating a 1/1 Thopter artifact creature token.
2. When the Thopter enters, Mm'menon triggers twice due to Yarok, putting a +1/+1 counter on Thopter Squadron and Crystalline Crawler.
3. Activate Crystalline Crawler by removing a +1/+1 counter from it, adding 1.
4. Repeat.

This ingenious loop transforms a simple mechanical exchange into a self-sustaining engine by letting Thopter Squadron fuel its own token-manufacturing through Crystalline Crawler. You begin by stripping a counter from Thopter Squadron to mint a fresh Thopter token, which immediately catches the attention of Mm'menon, Uthros Exile; thanks to Yarok, the Desecrated doubling that trigger, the arriving artifact places fresh +1/+1 counters back onto both Thopter Squadron and Crystalline Crawler. You then cash in a counter from Crystalline Crawler for the exact mana needed to pay for the next activation, leaving you with an ever-growing board of thopters and counters.