Swamp

Cunning Lethemancer

At the beginning of your upkeep, each player discards a card.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Seizan, Perverter of Truth

At the beginning of each player's upkeep, that player loses 2 life and draws two cards.

Howling Golem

Whenever Howling Golem attacks or blocks, each player draws a card.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Black Market

Whenever a creature dies, put a charge counter on Black Market.
At the beginning of your first main phase, add {B} for each charge counter on Black Market.

Font of Mythos

At the beginning of each player's draw step, that player draws two additional cards.

Temple Bell

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Magus of the Coffers

{2}, {T}: Add {B} for each Swamp you control.

Runed Servitor

When Runed Servitor dies, each player draws a card.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Sol Ring

Extraplanar Lens

Imprint — When Extraplanar Lens enters, you may exile target land you control.
Whenever a land with the same name as the exiled card is tapped for mana, its controller adds one mana of any type that land produced.

Liliana of the Dark Realms

+1: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.
−3: Target creature gets +X/+X or -X/-X until end of turn, where X is the number of Swamps you control.
−6: You get an emblem with "Swamps you control have '{T}: Add {B}{B}{B}{B}.'"

Howling Mine

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.