Szarel, Genesis Shepherd + Crystalline Crawler + Umbral Collar Zealot + Persistent Specimen

Szarel, Genesis Shepherd

Crystalline Crawler

Umbral Collar Zealot

Persistent Specimen

How it works

1. Activate Persistent Specimen by paying 2, returning it from your graveyard to the battlefield.
2. Activate Umbral Collar Zealot by sacrificing Persistent Specimen.
3. When Persistent Specimen is sacrificed, Szarel triggers, putting a number of +1/+1 counters equal to Szarel's power on Crystalline Crawler.
4. Resolve the Umbral Collar Zealot ability.
5. Activate Crystalline Crawler three times by removing three +1/+1 counters from it, adding 2.
6. Repeat.

This clever loop hinges on Szarel, Genesis Shepherd translating the repeated sacrifice of Persistent Specimen—which keeps pulling itself right back from the graveyard—into a massive influx of +1/+1 counters. Each time Umbral Collar Zealot puts that specimen into the dirt, Szarel's trigger floods Crystalline Crawler with counters, which can then be stripped away for mana to pay for Persistent Specimen's activation cost. Meanwhile, Umbral Collar Zealot's sacrifice outlet lets you continually dig through your library with surveil triggers while fueling the entire engine into an infinite spectacle of death and rebirth.