Gravecrawler, Rooftop Storm, and Nim Shambler

Prerequisites

• Gravecrawler on the battlefield
• Rooftop Storm on the battlefield
• Nim Shambler on the battlefield

Steps

1. Activate Nim Shambler's ability by sacrificing Gravecrawler, regenerate Nim Shambler
2. Cast Gravecrawler from your graveyard by paying
3. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers
• Infinite storm count