Peregrine Drake | Shrieking Drake | Roaming Throne

Cards

You control lands that can produce at least ({2} magic symbol) ({U} magic symbol) .

Cast
Peregrine Drake by paying ({4} magic symbol) ({U} magic symbol) .
When
Peregrine Drake enters the battlefield, it triggers itself twice due to Panharmonicon.
Resolve one
Peregrine Drake trigger, untapping five lands.
Activate those lands by tapping them to add at least ({2} magic symbol) ({U} magic symbol) .
Resolve the remaining
Peregrine Drake trigger, untapping five lands.
Activate those lands by tapping them to add at least ({2} magic symbol) ({U} magic symbol) .
Cast
Shrieking Drake by paying ({U} magic symbol) .
When
Shrieking Drake enters the battlefield, it triggers itself twice due to Panharmonicon, returning itself and
Peregrine Drake from the battlefield to your hand.
Repeat.
If you can produce at least one additional mana in step 4, this combo produces infinite mana.