The Thirteenth Doctor + Crystalline Crawler + Gravecrawler + Viscera Seer

The Thirteenth Doctor

Crystalline Crawler

Gravecrawler

Viscera Seer

How it works

1. Activate Viscera Seer by sacrificing Gravecrawler, causing you to scry 1.
2. Cast Gravecrawler from your graveyard by paying .
3. The Thirteenth Doctor's first ability triggers, putting a +1/+1 counter on Crystalline Crawler.
4. Activate Crystalline Crawler's first ability by removing a +1/+1 counter from it, adding .
5. Repeat.

This loop transforms Gravecrawler into an endless offering for Viscera Seer, feeding a seamless cycle of sacrifice and rebirth from your graveyard. As Gravecrawler hits the stack from the graveyard, The Thirteenth Doctor's paradox ability triggers off the zone change, rewarding you by dropping a +1/+1 counter onto Crystalline Crawler. You can then immediately cash in that very counter using Crystalline Crawler's mana ability to generate the black mana needed to recast Gravecrawler all over again.