Have

Knight of Dusk

{B}{B}: Destroy target creature blocking Knight of Dusk.

Don't Have

Drudge Skeletons

{B}: Regenerate Drudge Skeletons. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Getting

Okiba-Gang Shinobi

Ninjutsu {3}{B} ({3}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Okiba-Gang Shinobi deals combat damage to a player, that player discards two cards.

Removal

Dark Banishing

Destroy target nonblack creature. It can't be regenerated.

Mind Sludge

Target player discards a card for each Swamp you control.

Urborg Skeleton

Kicker {3} (You may pay an additional {3} as you cast this spell.)
{B}: Regenerate Urborg Skeleton.
If Urborg Skeleton was kicked, it enters with a +1/+1 counter on it.

Wicked Akuba

{B}: Target player dealt damage by Wicked Akuba this turn loses 1 life.

Midnight Covenant

Enchant creature
Enchanted creature has "{B}: This creature gets +1/+1 until end of turn."

Undercity Shade

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
{B}: Undercity Shade gets +1/+1 until end of turn.

Rathi Trapper

Howl from Beyond

Target creature gets +X/+0 until end of turn.

Steel Wall

Royal Assassin

Vampiric Link

Enchant creature
Whenever enchanted creature deals damage, you gain that much life.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

Dross Prowler

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Razortooth Rats

Terror

Destroy target nonartifact, nonblack creature. It can't be regenerated.

Swamp

Mortivore

Mortivore's power and toughness are each equal to the number of creature cards in all graveyards.
{B}: Regenerate Mortivore. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Looming Shade

{B}: Looming Shade gets +1/+1 until end of turn.

Woebearer

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Woebearer deals combat damage to a player, you may return target creature card from your graveyard to your hand.

Cabal Interrogator

{X}{B}, {T}: Target player reveals X cards from their hand and you choose one of them. That player discards that card. Activate only as a sorcery.

Crypt Sliver

All Slivers have "{T}: Regenerate target Sliver."

Rend Flesh

Distress

Target player reveals their hand. You choose a nonland card from it. That player discards that card.

Necroplasm

At the beginning of your upkeep, put a +1/+1 counter on Necroplasm.
At the beginning of your end step, destroy each creature with mana value equal to the number of +1/+1 counters on Necroplasm.
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.)

Mandatory

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}