Shadowheart, Dark Justiciar

{1}{B}, {T}, Sacrifice another creature: Draw X cards, where X is that creature's power.
Choose a Background (You can have a Background as a second commander.)

Sonic Screwdriver

{T}: Add one mana of any color.
{1}, {T}: Untap another target artifact.
{2}, {T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{3}, {T}: Target creature can't be blocked this turn.

Thought Vessel

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

Thran Dynamo

Hive of the Eye Tyrant

If you control two or more other lands, Hive of the Eye Tyrant enters tapped.
{T}: Add {B}.
{3}{B}: Until end of turn, Hive of the Eye Tyrant becomes a 3/3 black Beholder creature with menace and "Whenever this creature attacks, exile target card from defending player's graveyard." It's still a land.

Swamp

Voltaic Servant

At the beginning of your end step, untap target artifact.

Patriar's Seal

{T}: Add one mana of any color.
{1}, {T}: Untap target legendary creature you control.

Haunted One

Commander creatures you own have "Whenever this creature becomes tapped, it and other creatures you control that share a creature type with it each get +2/+0 and gain undying until end of turn." (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Manifold Key

{1}, {T}: Untap another target artifact.
{3}, {T}: Target creature can't be blocked this turn.

Puppet Strings

{2}, {T}: You may tap or untap target creature.

Staff of Domination

{1}: Untap Staff of Domination.
{2}, {T}: You gain 1 life.
{3}, {T}: Untap target creature.
{4}, {T}: Tap target creature.
{5}, {T}: Draw a card.

Cabal Coffers

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

Magewright's Stone

{1}, {T}: Untap target creature that has an activated ability with {T} in its cost.

Jet Medallion

Black spells you cast cost {1} less to cast.

Sol Ring

Witch's Cottage

({T}: Add {B}.)
Witch's Cottage enters tapped unless you control three or more other Swamps.
When Witch's Cottage enters untapped, you may put target creature card from your graveyard on top of your library.

Cabal Stronghold

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

Gilded Lotus

Galvanic Key

Urborg, Tomb of Yawgmoth

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

Dross Scorpion

Whenever Dross Scorpion or another artifact creature dies, you may untap target artifact.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.