Missy, Phyrexian Altar, and Dulcet Sirens

Prerequisites

• Missy on the battlefield
• Phyrexian Altar on the battlefield
• Dulcet Sirens on the battlefield

Steps

1. Activate Phyrexian Altar by sacrificing Dulcet Sirens, adding
2. When Dulcet Sirens dies, Missy's first ability triggers, returning Dulcet Sirens from your graveyard to the battlefield face down as a 2/2 Cyberman artifact creature
3. Activate Dulcet Sirens's morph ability by paying , turning it face up
4. Repeat

Results

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