Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

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.

Gurmag Angler

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

Seething Song

Cabal Ritual

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

Kaervek's Torch

As long as Kaervek's Torch is on the stack, spells that target it cost {2} more to cast.
Kaervek's Torch deals X damage to any target.

Lotus Petal

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

Whirlpool Rider

When Whirlpool Rider enters, shuffle the cards from your hand into your library, then draw that many cards.

Dark Ritual

Manamorphose

Add two mana in any combination of colors.
Draw a card.

Sulfur Vent

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

Chromatic Sphere

{1}, {T}, Sacrifice Chromatic Sphere: Add one mana of any color. Draw a card.

Jace's Erasure

Whenever you draw a card, you may have target player mill a card.

Shambling Attendants

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Energy Tap

Tap target untapped creature you control. If you do, add an amount of {C} equal to that creature's mana value.

Saprazzan Skerry

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

Careful Study

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.

Cavern Harpy

Flying
When Cavern Harpy enters, return a blue or black creature you control to its owner's hand.
Pay 1 life: Return Cavern Harpy to its owner's hand.

Ancient Spring

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