The Thirteenth Doctor + Squee, the Immortal + Crystalline Crawler + Ashnod's Altar + Branching Evolution

The Thirteenth Doctor

Squee, the Immortal

Crystalline Crawler

Ashnod's Altar

Branching Evolution

How it works

1. Activate Ashnod's Altar by sacrificing Squee, adding CC.
2. Cast Squee from your graveyard by paying 1.
3. The Thirteenth Doctor's first ability triggers, putting two +1/+1 counters on Crystalline Crawler.
4. Activate Crystalline Crawler's first ability twice by removing two +1/+1 counters from it, adding .
5. Repeat.

This loop turns Squee, the Immortal into an endlessly renewable sacrifice engine by leveraging his ability to be recast right out of your graveyard. Ashnod's Altar provides the colorless mana and immediate death trigger to feed the cycle, while Branching Evolution steps in to double the counters generated by The Thirteenth Doctor whenever Squee enters the battlefield from exile. Those doubled counters land directly on Crystalline Crawler, which conveniently turns them right back into the colored mana you need to recast Squee, netting infinite colorless mana and storm count in the process.