Cabal Coffers

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

Withengar Unbound

Flying, intimidate, trample (A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a player loses the game, put thirteen +1/+1 counters on Withengar Unbound.

Elbrus, the Binding Blade

Equipped creature gets +1/+0.
When equipped creature deals combat damage to a player, unattach Elbrus, then transform it.
Equip {1}

Elbrus, the Binding Blade // Withengar Unbound

Dark Ritual

Dauthi Warlord

Shadow (This creature can block or be blocked by only creatures with shadow.)
Dauthi Warlord's power is equal to the number of creatures on the battlefield with shadow.

Contamination

At the beginning of your upkeep, sacrifice this enchantment unless you sacrifice a creature.
If a land is tapped for mana, it produces {B} instead of any other type and amount.

Clockwork Droid

You may exert this creature as it attacks. When you do, it can't be blocked this turn and you scry 1. (An exerted creature won't untap during your next untap step. To scry 1, look at the top card of your library. You may put that card on the bottom.)

Thran Dynamo

Dauthi Horror

Shadow (This creature can block or be blocked by only creatures with shadow.)
This creature can't be blocked by white creatures.

Changeling Outcast

Changeling (This card is every creature type.)
This creature can't block and can't be blocked.

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Urborg, Tomb of Yawgmoth

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

Dauthi Slayer

Shadow (This creature can block or be blocked by only creatures with shadow.)
This creature attacks each combat if able.

Dauthi Ghoul

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever a creature with shadow dies, put a +1/+1 counter on this creature.

Dauthi Jackal

Shadow (This creature can block or be blocked by only creatures with shadow.)
{B}{B}, Sacrifice this creature: Destroy target blocking creature.

Tormented Soul

This creature can't block and can't be blocked.

Dauthi Voidwalker

Shadow (This creature can block or be blocked by only creatures with shadow.)
If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.
{T}, Sacrifice this creature: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Sol Ring

Arcane Signet

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

Swamp

Nether Traitor

Haste
Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever another creature is put into your graveyard from the battlefield, you may pay {B}. If you do, return this card from your graveyard to the battlefield.