Port of Karfell can tap to produce at least ({3} magic symbol) ({U} magic symbol) ({B} magic symbol) ({B} magic symbol) .
Steps
Activate any number of other lands you control by tapping them, adding at least ({3} magic symbol) ({U} magic symbol) ({B} magic symbol) ({B} magic symbol) .
Activate
Zuran Orb by sacrificing a land other than
Port of Karfell, causing you to gain 2 life.
Repeat step 2 until you control no other lands except
Port of Karfell.
Activate
Port of Karfell's second ability by paying ({3} magic symbol) ({U} magic symbol) ({B} magic symbol) ({B} magic symbol) , tapping and sacrificing it, causing you to mill four cards and return
Lumra from your graveyard to the battlefield tapped.
Lumra enters the battlefield and dies as a state-based action due to having 0 toughness.
Lumra's enter-the-battlefield ability triggers, causing you to mill four cards and return all land cards from your graveyard to the battlefield tapped.
When the lands enter the battlefield,
Amulet of Vigor triggers that many times, untapping the lands.
Repeat.
Results
Infinite death triggers.
Infinite ETB.
Infinite landfall triggers.
Infinite lifegain.
Infinite lifegain triggers.
Infinite LTB.
Infinite mana lands you control can produce.
Infinite sacrifice triggers.
Infinite self-mill.
Put all land cards from your library and graveyard onto the battlefield.