Missy, Skirk Alarmist, Intruder Alarm, and Ashnod's Altar

Prerequisites

• Missy on the battlefield
• Skirk Alarmist on the battlefield
• Intruder Alarm on the battlefield
• Ashnod's Altar on the battlefield
• You control another nontoken nonartifact creature

Steps

1. Activate Ashnod's Altar by sacrificing another nontoken nonartifact creature, adding
2. When the creature dies, Missy's first ability triggers, returning the creature from your graveyard to the battlefield face down as a 2/2 Cyberman artifact creature
3. When the creature enters the battlefield, Intruder Alarm triggers, untapping all creatures
4. Activate Skirk Alarmist by tapping it, turning the creature face up
5. Repeat

Results

• Infinite colorless mana
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mana creatures you control can produce
• Infinite sacrifice triggers
• Infinite untap of all creatures