Sydri, Galvanic Genius, Cauldron Familiar, Witch's Oven, and Intruder Alarm

Prerequisites

• Sydri, Galvanic Genius on the battlefield
• Cauldron Familiar on the battlefield
• Witch's Oven on the battlefield
• Intruder Alarm on the battlefield
• Witch's Oven does not have summoning sickness
• available

Steps

1. Activate Sydri's first ability by paying , causing Witch's Oven to become an artifact creature until end of turn
2. Activate Witch's Oven by tapping it and sacrificing Cauldron Familiar, creating a Food artifact token
3. Activate Cauldron Familiar by sacrificing a Food token, returning it from your graveyard to the battlefield
4. When Cauldron Familar enters the battlefield, it and Intruder Alarm trigger
5. Resolve the Cauldron Familiar trigger, causing each opponent to lose 1 life and you to gain 1 life
6. Resolve the Intruder Alarm trigger, untapping all creatures
7. Repeat from step 2

Results

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