Berta, Wise Extrapolator, Intruder Alarm, and Ivy Lane Denizen

Prerequisites

• Berta, Wise Extrapolator on the battlefield
• Intruder Alarm on the battlefield
• Ivy Lane Denizen on the battlefield
• available

Steps

1. Activate Berta by paying and tapping it, creating a 0/0 Fractal creature token and putting a +1/+1 counter on it
2. When the Fractal enters, Intruder Alarm and Ivy Lane Denizen trigger
3. Resolve the Intruder Alarm trigger, untapping all creatures
4. Resolve the Ivy Lane Denizen trigger, putting a +1/+1 counter on Berta
5. Berta triggers, adding
6. Repeat

Results

• Infinite +1/+1 counters on a creature
• Infinite ETB
• Infinite creature tokens
• Infinite mana creatures you control can produce
• Infinite untap of creatures
• Infinite untap of creatures you control