Veiled Sentry

When an opponent casts a spell, if Veiled Sentry is an enchantment, Veiled Sentry becomes an Illusion creature with power and toughness each equal to that spell's mana value.

Thran Forge

{2}: Until end of turn, target nonartifact creature gets +1/+0 and becomes an artifact in addition to its other types.

Sage Owl

Flying
When Sage Owl enters, look at the top four cards of your library, then put them back in any order.

Neurok Transmuter

{U}: Target creature becomes an artifact in addition to its other types until end of turn.
{U}: Until end of turn, target artifact creature becomes blue and isn't an artifact.

Smash

Intervene

Counter target spell that targets a creature.

Island

Sea Scryer

Mana Leak

Counter target spell unless its controller pays {3}.

Magus of the Unseen

{1}{U}, {T}: Untap target artifact an opponent controls and gain control of it until end of turn. It gains haste until end of turn. When you lose control of the artifact, tap it.

Touchstone

{T}: Tap target artifact you don't control.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Viashino Heretic

{1}{R}, {T}: Destroy target artifact. Viashino Heretic deals damage to that artifact's controller equal to the artifact's mana value.

Quash

Counter target instant or sorcery spell. Search its controller's graveyard, hand, and library for all cards with the same name as that spell and exile them. Then that player shuffles.

Ghitu Encampment

Ghitu Encampment enters tapped.
{T}: Add {R}.
{1}{R}: Ghitu Encampment becomes a 2/1 red Warrior creature with first strike until end of turn. It's still a land. (It deals combat damage before creatures without first strike.)

Battering Craghorn

First strike
Morph {1}{R}{R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Lotus Petal

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

Rustmouth Ogre

Whenever Rustmouth Ogre deals combat damage to a player, you may destroy target artifact that player controls.

Mountain

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Fire Imp

When Fire Imp enters, it deals 2 damage to target creature.

Shattering Pulse

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Destroy target artifact.

Arcane Teachings

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature gets +2/+2 and has "{T}: This creature deals 1 damage to any target."

Abduction

Enchant creature
When Abduction enters, untap enchanted creature.
You control enchanted creature.
When enchanted creature dies, return that card to the battlefield under its owner's control.