Miirym, Sentinel Wyrm, Cloudstone Curio, Mothdust Changeling, and Phyrexian Altar

Prerequisites

• Miirym, Sentinel Wyrm on the battlefield
• Cloudstone Curio on the battlefield
• Mothdust Changeling in hand
• Phyrexian Altar on the battlefield
• available

Steps

1. Cast Mothdust Changeling by paying
2. Mothdust Changeling enters the battlefield, triggering Cloudstone Curio and Miirym
3. Resolve the Cloudstone Curio trigger, choosing not to return anything to your hand from the battlefield
4. Resolve the Miirym trigger, creating a token copy of Mothdust Changeling
5. The Mothdust Changeling token enters the battlefield, triggering Cloudstone Curio, returning the nontoken Mothdust Changeling from the battlefield to your hand
6. Activate Phyrexian Altar by sacrificing the Mothdust Changeling token, adding
7. Repeat

Results

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