Eternal Scourge + Young Deathclaws + Crystalline Crawler + Viscera Seer + Primal Vigor

Eternal Scourge

Young Deathclaws

Crystalline Crawler

Viscera Seer

Primal Vigor

How it works

1. Activate Eternal Scourge's scavenge ability, granted to it by Young Deathclaws, by paying 3 and exiling Eternal Scourge from your graveyard, putting six +1/+1 counters on Crystalline Crawler due to Primal Vigor.
2. Activate Crystalline Crawler six times by removing six +1/+1 counters from it, adding 6.
3. Cast Eternal Scourge from exile by paying 3.
4. Activate Viscera Seer by sacrificing Eternal Scourge.
5. Repeat.

This intricate engine turns a modest investment of mana into an infinite loop of sacrifices and triggers, beautifully orchestrated by Young Deathclaws granting its scavenge ability to Eternal Scourge right out of the graveyard. When you pay to scavenge Eternal Scourge, Primal Vigor doubles the resulting counters placed onto Crystalline Crawler, providing a surplus of raw material that Crystalline Crawler can immediately convert into any color of mana by removing those counters. You then simply cast Eternal Scourge straight from exile to feed it to Viscera Seer, letting you scry through your entire library while generating infinite death triggers and storm count. Because Eternal Scourge returns safely to exile upon resolution—ready to be cast again and scavenged once more—the cycle is completely self-sustaining.