Bojuka Bog

Bojuka Bog enters the battlefield tapped.
When Bojuka Bog enters the battlefield, exile target player's graveyard.
{T}: Add {B}.

Spark Double

You may have Spark Double enter the battlefield as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Despark

Exile target permanent with mana value 4 or greater.

Orzhov Signet

Command Tower

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

Damn

Destroy target creature. A creature destroyed this way can't be regenerated.
Overload {2}{W}{W} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Haystack

{2}, {T}: Target creature you control phases out. (Treat it and anything attached to it as though they don't exist until your next turn.)

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Sol Ring

Talisman of Hierarchy

{T}: Add {C}.
{T}: Add {W} or {B}. Talisman of Hierarchy deals 1 damage to you.

Solemn Simulacrum

When Solemn Simulacrum enters the battlefield, 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.

Arcane Signet

Cruel Celebrant

Whenever Cruel Celebrant or another creature or planeswalker you control dies, each opponent loses 1 life and you gain 1 life.

Athreos, Shroud-Veiled

Indestructible
As long as your devotion to white and black is less than seven, Athreos isn't a creature.
At the beginning of your end step, put a coin counter on another target creature.
Whenever a creature with a coin counter on it dies or is put into exile, return that card to the battlefield under your control.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.