Lathliss, Dragon Queen, Boneyard Scourge, and Phyrexian Altar

Prerequisites

• Lathliss, Dragon Queen on the battlefield
• Boneyard Scourge on the battlefield
• Phyrexian Altar on the battlefield
• You control at least one additional Dragon

Steps

1. Activate Phyrexian Altar by sacrificing Boneyard Scourge, adding
2. Activate Phyrexian Altar by sacrificing another Dragon, adding
3. When the Dragon dies, Boneyard Scourge triggers, causing you to pay to return it from your graveyard to the battlefield
4. When Boneyard Scourge enters the battlefield, Lathliss triggers, creating a 5/5 Dragon creature token
5. Repeat

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers