Dark Ritual

Cabal Ritual

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

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Pieces of the Puzzle

Reveal the top five cards of your library. Put up to two instant and/or sorcery cards from among them into your hand and the rest into your graveyard.

Seething Song

Serpentine Curve

Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is one plus the total number of instant and sorcery cards you own in exile and in your graveyard.

Dispel

Chromatic Star

{1}, {T}, Sacrifice Chromatic Star: Add one mana of any color.
When Chromatic Star is put into a graveyard from the battlefield, draw a card.

Nightscape Familiar

Blue spells and red spells you cast cost {1} less to cast.
{1}{B}: Regenerate Nightscape Familiar.