Lumra, Bellow of the Woods | Port of Karfell | Spelunking

(and one other card)

Lumra in your graveyard.
All other permanents on the battlefield.
You can produce at least ({3} magic symbol) ({U} magic symbol) ({B} magic symbol) ({B} magic symbol) between sacrificing lands excluding
Port of Karfell to
Squandered Resources and/or by tapping those lands for mana.

If desired, activate any number of other mana-producing lands you control by tapping them, adding at least ({1} magic symbol) for each land tapped this way.
Activate
Squandered Resources by sacrificing a mana-producing land other than
Port of Karfell, adding ({U} magic symbol) or ({B} magic symbol) if possible, or any other type of mana otherwise.
Repeat step 2 until you control no other mana-producing 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 untapped due to
Spelunking.
Repeat.