Lathliss, Dragon Queen, Sneak Attack, Cloudstone Curio, and Phyrexian Altar

Prerequisites

• Lathliss, Dragon Queen on the battlefield
• Sneak Attack on the battlefield
• Cloudstone Curio on the battlefield
• Phyrexian Altar on the battlefield
• You have a Dragon creature card in hand
• available

Steps

1. Activate Sneak Attack by paying , putting any Dragon from your hand onto the battlefield
2. The Dragon enters the battlefield, triggering Cloudstone Curio and Lathliss
3. Resolve the Cloudstone Curio trigger, choosing not to return anything to your hand from the battlefield
4. Resolve the Lathliss trigger, creating a 5/5 Dragon creature token
5. The Dragon token enters the battlefield, triggering Cloudstone Curio, returning the nontoken Dragon from the battlefield to your hand
6. Activate Phyrexian Altar by sacrificing the Dragon token, adding
7. Repeat

Results

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