Enduring Tenacity

Whenever you gain life, target opponent loses that much life.
When Enduring Tenacity dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Ancient Tomb

{T}: Add {C}{C}. This land deals 2 damage to you.

Dakmor Salvage

This land enters tapped.
{T}: Add {B}.
Dredge 2 (If you would draw a card, you may mill two cards instead. If you do, return this card from your graveyard to your hand.)

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Blood Artist

Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Sengir, the Dark Baron

Flying
Whenever another creature dies, put two +1/+1 counters on Sengir.
Whenever another player loses the game, you gain life equal to that player's life total as the turn began.
Partner (You can have two commanders if both have partner.)

Mikokoro, Center of the Sea

{T}: Add {C}.
{2}, {T}: Each player draws a card.

Grievous Wound

Enchant player
Enchanted player can't gain life.
Whenever enchanted player is dealt damage, they lose half their life, rounded up.

Cabal Coffers

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

Falthis, Shadowcat Familiar

Commanders you control have menace and deathtouch.
Partner (You can have two commanders if both have partner.)

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

Sol Ring

Swamp

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Reliquary Tower

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

Urborg, Tomb of Yawgmoth

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

Bloodletter of Aclazotz

Flying
If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)

Field of the Dead

This land enters tapped.
{T}: Add {C}.
Whenever this land or another land you control enters, if you control seven or more lands with different names, create a 2/2 black Zombie creature token.