Gravecrawler + Rooftop Storm + Altar of Dementia

Gravecrawler
Rooftop Storm
Altar of Dementia

Requires
All permanents on the battlefield. You control at least one additional Zombie.
Steps
  1. Activate Altar of Dementia by sacrificing Gravecrawler, causing target player to mill two cards
  2. Cast Gravecrawler from your graveyard by paying 0
  3. Repeat
Results
Infinite mill. Infinite ETB. Infinite LTB. Infinite sacrifice triggers. Infinite storm count.