Missy, Skirk Alarmist, Thornbite Staff, and Altar of Dementia

Prerequisites

• Missy on the battlefield
• Skirk Alarmist on the battlefield
• Thornbite Staff on the battlefield
• Altar of Dementia on the battlefield
• You control another nontoken nonartifact creature
• Thornbite Staff attached to Skirk Alarmist

Steps

1. Activate Altar of Dementia by sacrificing another nontoken nonartifact creature
2. When the creature dies, Missy's first ability and Skirk Alarmist trigger
3. Resolve the Missy ability, returning the creature from your graveyard to the battlefield face down as a 2/2 Cyberman artifact creature
4. Resolve the Skirk Alarmist trigger, untapping it
5. Resolve the Altar of Dementia ability from step 1, causing target player to mill cards equal to the sacrificed creature's power
6. Activate Skirk Alarmist by tapping it, turning the creature face up
7. Repeat

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mill
• Infinite sacrifice triggers
• Infinite self-mill