Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Cabal Coffers

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

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Everglades

Everglades enters tapped.
When Everglades enters, sacrifice it unless you return an untapped Swamp you control to its owner's hand.
{T}: Add {C}{B}.

Arcane Signet

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

Sceptre of Eternal Glory

{T}: Add one mana of any color.
{T}: Add three mana of any one color. Activate only if you control three or more lands with the same name.

Charcoal Diamond

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

Swamp

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Sol Ring

Castle Locthwain

Castle Locthwain enters tapped unless you control a Swamp.
{T}: Add {B}.
{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.