Blade of the Oni

Menace
Equipped creature has base power and toughness 5/5, has menace, and is a black Demon in addition to its other colors and types.
Reconfigure {2}{B}{B} ({2}{B}{B}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Traitorous Blood

Gain control of target creature until end of turn. Untap it. It gains trample and haste until end of turn.

Bothersome Quasit

Menace
Goaded creatures your opponents control can't block.
Whenever you cast a noncreature spell, goad target creature an opponent controls. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Charcoal Diamond

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

Skulltap

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Bog Witch

Krark, the Thumbless

Whenever you cast an instant or sorcery spell, flip a coin. If you lose the flip, return that spell to its owner's hand. If you win the flip, copy that spell, and you may choose new targets for the copy.
Partner (You can have two commanders if both have partner.)

Bloody Betrayal

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Iron Myr

Costly Plunder

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards.

Wrangle

Gain control of target creature with power 4 or less until end of turn. Untap that creature. It gains haste until end of turn.

Metallic Mastery

Gain control of target artifact until end of turn. Untap that artifact. It gains haste until end of turn.

Keskit, the Flesh Sculptor

{T}, Sacrifice three other artifacts and/or creatures: Look at the top three cards of your library. Put two of them into your hand and the other into your graveyard.
Partner (You can have two commanders if both have partner.)

Village Rites

Leaden Myr

Mark of Mutiny

Gain control of target creature until end of turn. Put a +1/+1 counter on it and untap it. That creature gains haste until end of turn. (It can attack and {T} this turn.)

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Bankrupt in Blood

As an additional cost to cast this spell, sacrifice two creatures.
Draw three cards.

Reckoner's Bargain

As an additional cost to cast this spell, sacrifice an artifact or creature.
You gain life equal to the sacrificed permanent's mana value. Draw two cards.

Claim the Firstborn

Gain control of target creature with mana value 3 or less until end of turn. Untap that creature. It gains haste until end of turn.