Saprazzan Skerry

Saprazzan Skerry enters the battlefield 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.

Rush of Knowledge

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

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.

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.

Careful Study

Ancient Spring

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

Dark Ritual

Island

Brainspoil

Destroy target creature that isn't enchanted. It can't be regenerated.
Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Gurmag Angler

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

Chromatic Sphere

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

Serum Visions

Manamorphose

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

Rolling Thunder

Rolling Thunder deals X damage divided as you choose among any number of targets.

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.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Sulfur Vent

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