Graceful Reprieve, Phyrexian Altar, Cloud Key, and Living Lightning

Prerequisites

• Graceful Reprieve in hand
• Phyrexian Altar on the battlefield
• Cloud Key on the battlefield
• Living Lightning on the battlefield
• "Instant" chosen with Cloud Key
• available

Steps

1. Cast Graceful Reprieve by paying , targeting Living Lightning
2. Activate Phyrexian Altar by sacrificing Living Lightning, adding
3. When Living Lightning dies, it and Graceful Reprieve trigger
4. Resolve the Living Lightning trigger, returning Graceful Reprieve from your graveyard to your hand
5. Resolve the Graceful Reprieve trigger, returning Living Lightning from your graveyard to the battlefield
6. Repeat

Results

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