Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Profane Tutor

Suspend 2—{1}{B} (Rather than cast this card from your hand, pay {1}{B} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Search your library for a card, put that card into your hand, then shuffle.

Subterranean Hangar

Subterranean Hangar enters tapped.
{T}: Put a storage counter on Subterranean Hangar.
{T}, Remove any number of storage counters from Subterranean Hangar: Add {B} for each storage counter removed this way.

Sickening Dreams

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

Varragoth, Bloodsky Sire

Deathtouch
Boast — {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)

Sol Ring

Elixir of Immortality

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

Swamp

Thespian's Stage

{T}: Add {C}.
{2}, {T}: Thespian's Stage becomes a copy of target land, except it has this ability.

Glacial Chasm

Cumulative upkeep—Pay 2 life. (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.)
When Glacial Chasm enters, sacrifice a land.
Creatures you control can't attack.
Prevent all damage that would be dealt to you.

Peat Bog

Peat Bog enters tapped with two depletion counters on it.
{T}, Remove a depletion counter from Peat Bog: Add {B}{B}. If there are no depletion counters on Peat Bog, sacrifice it.

Polluted Mire

Polluted Mire enters tapped.
{T}: Add {B}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Crystal Vein

{T}: Add {C}.
{T}, Sacrifice Crystal Vein: Add {C}{C}.

Ebon Stronghold

Ebon Stronghold enters tapped.
{T}: Add {B}.
{T}, Sacrifice Ebon Stronghold: Add {B}{B}.

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

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.

Dark Sphere

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

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Mage-Ring Network

{T}: Add {C}.
{1}, {T}: Put a storage counter on Mage-Ring Network.
{T}, Remove any number of storage counters from Mage-Ring Network: Add {C} for each storage counter removed this way.

Dark Ritual

Desert of the Glorified

Desert of the Glorified enters tapped.
{T}: Add {B}.
Cycling {1}{B} ({1}{B}, Discard this card: Draw a card.)