Hapless Researcher

Sacrifice Hapless Researcher: Draw a card, then discard a card.

Thought Scour

Target player mills two cards.
Draw a card.

Songs of the Damned

Add {B} for each creature card in your graveyard.

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Skirge Familiar

Cabal Ritual

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

Snow-Covered Swamp

Snow-Covered Island

Exhume

Each player puts a creature card from their graveyard onto the battlefield.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Greater Mossdog

Dredge 3 (If you would draw a card, you may mill three cards instead. If you do, return this card from your graveyard to your hand.)

Snow-Covered Mountain

Rush of Knowledge

Draw cards equal to the highest mana value among permanents you control.

Ancient Spring

Ancient Spring enters tapped.
{T}: Add {U}.
{T}, Sacrifice Ancient Spring: Add {W}{B}.

Dark Ritual

Sulfur Vent

Sulfur Vent enters tapped.
{T}: Add {B}.
{T}, Sacrifice Sulfur Vent: Add {U}{R}.

Geothermal Crevice

Geothermal Crevice enters tapped.
{T}: Add {R}.
{T}, Sacrifice Geothermal Crevice: Add {B}{G}.

Careful Study

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Mental Note

Consume Spirit

Spend only black mana on X.
Consume Spirit deals X damage to any target and you gain X life.

Stinkweed Imp

Flying
Whenever Stinkweed Imp deals combat damage to a creature, destroy that creature.
Dredge 5 (If you would draw a card, you may mill five cards instead. If you do, return this card from your graveyard to your hand.)

Burnt Offering

As an additional cost to cast this spell, sacrifice a creature.
Add X mana in any combination of {B} and/or {R}, where X is the sacrificed creature's mana value.