Steelfin Whale, and Banishing Knack

Prerequisites

• Steelfin Whale on the battlefield
• Banishing Knack in hand
• available

Steps

1. Cast Banishing Knack by paying , giving Steelfin Whale an activated ability until end of turn
2. Activate Steelfin Whale by tapping it, returning the free artifact from the battlefield to your hand
3. Cast that artifact by paying
4. When that artifact enters the battlefield, it triggers Steelfin Whale, untapping it
5. Repeat from step 2

Results

• Infinite ETB
• Infinite LTB
• Infinite storm count
• Infinite mana creatures you control can produce
• Infinite untap of creatures you control