Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Paragon of Open Graves

Other black creatures you control get +1/+1.
{2}{B}, {T}: Another target black creature you control gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Swift End

Destroy target creature or planeswalker. You lose 2 life. (Then exile this card. You may cast the creature later from exile.)

Murderous Rider

Lifelink
When Murderous Rider dies, put it on the bottom of its owner's library.

Murderous Rider // Swift End

Loyal Subordinate

Menace (This creature can't be blocked except by two or more creatures.)
Lieutenant — At the beginning of combat on your turn, if you control your commander, each opponent loses 3 life.

Reassembling Skeleton

{1}{B}: Return Reassembling Skeleton from your graveyard to the battlefield tapped.

Dread Presence

Whenever a Swamp you control enters, choose one —
• You draw a card and you lose 1 life.
• Dread Presence deals 2 damage to any target and you gain 2 life.

Commander Greven il-Vec

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
When Commander Greven il-Vec enters, sacrifice a creature.

Dark Ritual

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Predator, Flagship

{2}: Target creature gains flying until end of turn.
{5}, {T}: Destroy target creature with flying.

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.