The Thirteenth Doctor + Crystalline Crawler + Gravecrawler + Altar of Dementia

The Thirteenth Doctor

Crystalline Crawler

Gravecrawler

Altar of Dementia

How it works

1. Activate Altar of Dementia by sacrificing Gravecrawler, causing target player to mill cards equal to Gravecrawler's power.
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 ingenious loop turns Altar of Dementia into a mill-based win condition by leveraging Gravecrawler's unique ability to be cast directly from your graveyard as long as you control a Zombie. Each time you recast Gravecrawler, The Thirteenth Doctor sees a spell cast from somewhere other than your hand and rewards 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 pay for Gravecrawler's recurrence, feeding the Altar over and over again to mill out your opponents.