Force of Will

You may pay 1 life and remove a blue card in your hand from the game instead of paying Force of Will's casting cost. Effects that prevent or redirect damage cannot be used to counter this loss of life. Counter target spell.

Cavern of Souls

As Cavern of Souls enters the battlefield, choose a creature type. {T}: Add {1} to your mana pool. {T}: Add one mana of any color to your mana pool. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Containment Priest

Flash If a nontoken creature would enter the battlefield and it wasn't cast, exile it instead.

Hunter Sliver

All Slivers have provoke. (When a Sliver attacks, its controller may have target creature defending player controls untap and block it if able.)

Galerider Sliver

Sliver creatures you control have flying.

Syphon Sliver

Sliver creatures you control have lifelink. (Damage dealt by a Sliver creature you control also causes you to gain that much life.)

Striking Sliver

Sliver creatures you control have first strike. (They deal combat damage before creatures without first strike.)

Predatory Sliver

Sliver creatures you control get +1/+1.

Sliver Hive

{T}: Add {1} to your mana pool. {T}: Add one mana of any color to your mana pool. Spend this mana only to cast a Sliver spell. {5}, {T}: Put a 1/1 colorless Sliver creature token onto the battlefield. Activate this ability only if you control a Sliver.

Aether Vial

At the beginning of your upkeep, you may put a charge counter on ?ther Vial. {T}: You may put a creature card with converted mana cost equal to the number of charge counters on ?ther Vial from your hand onto the battlefield.

Darkheart Sliver

All Slivers have "Sacrifice this creature: You gain 3 life."

Sinew Sliver

All Slivers get +1/+1.

Mutavault

{T}: Add {1} to your mana pool. {1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Ancient Ziggurat

{T}: Add one mana of any color to your mana pool. Spend this mana only to cast creature spells.

Karakas

{T}: Add {W} to your mana pool. {T}: Return target legendary creature to its owner's hand.

Ethersworn Canonist

Each player who has played a nonartifact spell this turn can't play additional nonartifact spells.

Hibernation Sliver

Each Sliver gains "Pay 2 life: Return this creature to owner's hand."

Crystalline Sliver

Slivers cannot be the target of spells or abilities.

Muscle Sliver

All Slivers get +1/+1.

Winged Sliver

All slivers gain flying.

Harmonic Sliver

All Slivers have "When this creature comes into play, destroy target artifact or enchantment."

Sidewinder Sliver

All Slivers have flanking. (Whenever a creature without flanking blocks a Sliver, the blocking creature gets -1/-1 until end of turn.)

Unclaimed Territory

Leyline of the Void

If Leyline of the Void is in your opening hand, you may begin the game with it on the battlefield. If a card would be put into an opponent's graveyard from anywhere, exile it instead.