Thousand-Faced Shadow, Cloudstone Curio, and Great Whale

Prerequisites

• Thousand-Faced Shadow in hand
• Cloudstone Curio on the battlefield
• Great Whale on the battlefield
• You control at least one other creature that can attack this turn
• You control up to seven lands that can tap to produce at least
• Great Whale does not have summoning sickness
• An opponent is unable to block and kill creatures you control

Steps

1. Declare Great Whale and any other creature as attackers
2. When they are unblocked, activate up to seven lands you control by tapping them, adding at least
3. Activate Thousand-Faced Shadow's ninjutsu ability by paying and returning the other attacking creature to your hand, putting Thousand-Faced Shadow from your hand onto the battlefield tapped and attacking
4. Thousand-Faced Shadow enters the battlefield, triggering itself and Cloudstone Curio
5. Resolve the Cloudstone Curio trigger, choosing not to return anything from the battlefield to your hand
6. Resolve the Thousand-Faced Shadow trigger, creating a token copy of Great Whale
7. The token Great Whale enters the battlefield, triggering itself and Cloudstone Curio
8. Resolve the Great Whale trigger, untapping up to seven lands you control
9. Resolve the Cloudstone Curio trigger, returning Thousand-Faced Shadow from the battlefield to your hand
10. Repeat from step 2

Results

• Infinite ETB
• Infinite LTB
• Infinite mana lands you control can produce