Enduring Renewal + Broodguard Elite + Crystalline Crawler + Ashnod's Altar

Enduring Renewal

Broodguard Elite

Crystalline Crawler

Ashnod's Altar

How it works

1. Cast Broodguard Elite for its warp cost by paying 1.
2. Activate Ashnod's Altar by sacrificing Broodguard Elite, adding CC.
3. When Broodguard Elite dies, it and Enduring Renewal trigger.
4. Resolve the Broodguard Elite trigger, putting a +1/+1 counter on Crystalline Crawler.
5. Resolve the Enduring Renewal trigger, returning Broodguard Elite from your graveyard to your hand.
6. Activate Crystalline Crawler by removing a +1/+1 counter from it, adding .
7. Repeat.

This loop is a masterclass in recycling, using Enduring Renewal's passive ability to catch Broodguard Elite every time it hits the graveyard and bounce it straight back to your hand. Once the Elite is sacrificed to Ashnod's Altar for colorless mana, its leave-the-battlefield trigger jumps into action to pump up Crystalline Crawler with a fresh +1/+1 counter. That counter can then be cashed in using Crystalline Crawler's active ability to generate the colored mana needed to recast Broodguard Elite for its warp cost, fueling an endless cycle that generates infinite mana, death triggers, and counters.