Urza, Lord High Artificer, Corridor Monitor, Banishing Knack, and Animar, Soul of Elements

Prerequisites

• Urza, Lord High Artificer on the battlefield
• Corridor Monitor in hand
• Banishing Knack in hand
• Animar, Soul of Elements on the battlefield
• available

Steps

1. Cast Banishing Knack by paying , targeting a creature you control that doesn't have summoning sickness
2. Cast Corridor Monitor by paying due to Animar
3. Animar triggers, putting a +1/+1 counter on it
4. When Corridor Monitor enters, it triggers, untapping the creature targeted by Banishing Knack
5. Activate Urza's first ability by tapping Corridor Monitor, adding
6. Activate the creature targeted by Banishing Knack by tapping it, returning Corridor Monitor from the battlefield to your hand
7. Repeat from step 2

Results

• Infinite +1/+1 counters on a creature
• Infinite ETB
• Infinite LTB
• Infinite storm count