Peregrine Drake and Skullsnatcher on the battlefield.
Skullsnatcher and Peregrine Drake do not have summoning sickness.
An opponent cannot block Skullsnatcher or Peregrine Drake.
You control up to five lands that can tap to produce at least ({2} magic symbol) ({U} magic symbol) ({U} magic symbol) ({B} magic symbol) .
Steps
Declare Peregrine Drake and Skullsnatcher as attackers.
When they aren't blocked, activate up to five lands you control by tapping them, adding at least ({2} magic symbol) ({U} magic symbol) ({U} magic symbol) ({B} magic symbol) .
Activate Thousand-Faced Shadow's ninjutsu ability by paying ({2} magic symbol) ({U} magic symbol) ({U} magic symbol) and returning Skullsnatcher from the battlefield to your hand, putting Thousand-Faced Shadow onto the battlefield from your hand tapped and attacking.
When Thousand-Faced Shadow enters the battlefield, it triggers, creating a token copy of Peregrine Drake that is tapped and attacking.
When the Peregrine Drake token enters the battlefield, it triggers, untapping up to five lands.
Activate Skullsnatcher's ninjutsu ability by paying ({B} magic symbol) and returning Thousand-Faced Shadow from the battlefield to your hand, putting Skullsnatcher onto the battlefield from your hand tapped and attacking.
Repeat from step 2.
Deal combat damage using the Peregrine Drake tokens, dealing infinite combat damage to the defending opponent.
If you control up to five lands that can tap to produce at least ({3} magic symbol) ({U} magic symbol) ({U} magic symbol) ({B} magic symbol) , this combo nets infinite mana.