Activate Mary Read and Anne Bonny by tapping it, causing you to draw a card and then discard an Island, Pirate or Vehicle card.
The discarded card is put on top of your library instead of into your graveyard due to Library of Leng.
Mary Read and Anne Bonny triggers, creating a tapped Treasure token.
When the Treasure enters the battlefield, Transplant Theorist triggers, causing you to draw a card and then discard an Island, Pirate or Vehicle card.
Repeat from step 2.

Infinite self-discard triggers

Infinite draw triggers

Infinite tapped Treasure tokens

Mary Read and Anne Bonny

Library of Leng

Transplant Theorist

Activate Mary Read and Anne Bonny by tapping it, causing you to draw a card and then discard an Island, Pirate or Vehicle card.
The discarded card is put on top of your library instead of into your graveyard due to Library of Leng.
Mary Read and Anne Bonny triggers, creating a tapped Treasure token.
When the Treasure enters the battlefield, Skyswimmer Koi triggers, causing you to draw a card and then discard an Island, Pirate or Vehicle card.
Repeat from step 2.

Skyswimmer Koi

Cast Sage of the Falls by paying {4}{U}.
When Sage of the Falls enters, it triggers, causing you to loot. The discarded card will be put on top of your library instead of into your graveyard due to Library of Leng.
Wan Shi Tong's second ability triggers, creating two 1/1 Spirit creature tokens.
When the Spirits enter, Sage of the Falls triggers twice.
Resolve the first trigger, choosing not to draw a card.
Resolve the second trigger, causing you to loot. The discarded card will be put on top of your library instead of into your graveyard due to Library of Leng.
Repeat from step 3.

Near-infinite ETB

Infinite looting

Near-infinite creature tokens

Wan Shi Tong, All-Knowing

Sage of the Falls

Activate Kitsa by tapping it, causing you to loot. The discarded card will be put on top of your library instead of into your graveyard due to Library of Leng.
Wan Shi Tong's second ability triggers, creating two 1/1 Spirit creature tokens.
When the Spirits enter, Intruder Alarm triggers twice, untapping all creatures twice.
Repeat.

Infinite ETB

Infinite creature tokens

Infinite mana creatures you control can produce

Infinite untap of creatures

Intruder Alarm

Kitsa, Otterball Elite

Activate Urza by paying {1}, causing you to loot. The discarded card will be put on top of your library instead of into your graveyard due to Library of Leng.
Wan Shi Tong's second ability triggers, creating two 1/1 Spirit creature tokens.
When the Spirits enter, Intruder Alarm triggers twice, untapping all creatures.
Activate Phyrexian Altar by sacrificing a Spirit, adding {1}.
Repeat.

Combos with "Library of Leng"