Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Lotus Petal

{T}, Sacrifice this artifact: Add one mana of any color.

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle this artifact and your graveyard into their owner's library.

Gargoyle Castle

{T}: Add {C}.
{5}, {T}, Sacrifice this land: Create a 3/4 colorless Gargoyle artifact creature token with flying.

Dark Sphere

{T}, Sacrifice this artifact: The next time a source of your choice would deal damage to you this turn, prevent half that damage, rounded down.

Spellbook

Sickening Dreams

As an additional cost to cast this spell, discard X cards.
Sickening Dreams deals X damage to each creature and each player.

Claws of Gix

{1}, Sacrifice a permanent: You gain 1 life.

Quicksand

{T}: Add {C}.
{T}, Sacrifice this land: Target attacking creature without flying gets -1/-2 until end of turn.

Dark Ritual

Shield Sphere

Defender
Whenever this creature blocks, put a -0/-1 counter on it.

Swamp

Halls of Mist

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Creatures that attacked during their controller's last turn can't attack.

Bojuka Bog

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

Maralen of the Mornsong

Players can't draw cards.
At the beginning of each player's draw step, that player loses 3 life, searches their library for a card, puts it into their hand, then shuffles.

Ornithopter

Zombie Infestation

Discard two cards: Create a 2/2 black Zombie creature token.

Ad Nauseam

Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value. You may repeat this process any number of times.

Dread Statuary

{T}: Add {C}.
{4}: This land becomes a 4/2 Golem artifact creature until end of turn. It's still a land.

Spawning Pool

This land enters tapped.
{T}: Add {B}.
{1}{B}: This land becomes a 1/1 black Skeleton creature with "{B}: Regenerate this creature" until end of turn. It's still a land. (If it regenerates, the next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Zuran Orb

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.