Thistledown Liege

Flash
Other white creatures you control get +1/+1.
Other blue creatures you control get +1/+1.

Long-Term Plans

Search your library for a card, then shuffle and put that card third from the top.

Pristine Skywise

Flying
Whenever you cast a noncreature spell, untap Pristine Skywise. It gains protection from the color of your choice until end of turn.

Honor of the Pure

Reverence

Creatures with power 2 or less can't attack you.

Qasali Pridemage

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{1}, Sacrifice Qasali Pridemage: Destroy target artifact or enchantment.

Wall of Denial

Defender, flying
Shroud (This creature can't be the target of spells or abilities.)

Island

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Unsummon

Return target creature to its owner's hand.

Coastal Tower

Coastal Tower enters tapped.
{T}: Add {W} or {U}.

Arcane Sanctum

Arcane Sanctum enters tapped.
{T}: Add {W}, {U}, or {B}.

Azorius First-Wing

Guile

Guile can't be blocked except by three or more creatures.
If a spell or ability you control would counter a spell, instead exile that spell and you may play that card without paying its mana cost.
When Guile is put into a graveyard from anywhere, shuffle it into its owner's library.

Plains

Azorius Signet

Elvish Hexhunter

{G/W}, {T}, Sacrifice Elvish Hexhunter: Destroy target enchantment.

Silver Drake

Flying
When Silver Drake enters, return a white or blue creature you control to its owner's hand.

Suture Priest

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Minister of Impediments

({W/U} can be paid with either {W} or {U}.)
{T}: Tap target creature.

Crookclaw Elder

Flying
Tap two untapped Birds you control: Draw a card.
Tap two untapped Wizards you control: Target creature gains flying until end of turn.

Witch Hunter

{T}: Witch Hunter deals 1 damage to target player or planeswalker.
{1}{W}{W}, {T}: Return target creature an opponent controls to its owner's hand.

Steel of the Godhead

Enchant creature
As long as enchanted creature is white, it gets +1/+1 and has lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)
As long as enchanted creature is blue, it gets +1/+1 and can't be blocked.

Dovescape

({W/U} can be paid with either {W} or {U}.)
Whenever a player casts a noncreature spell, counter that spell. That player creates X 1/1 white and blue Bird creature tokens with flying, where X is the spell's mana value.

Counterspell

Fatestitcher

{T}: You may tap or untap another target permanent.
Unearth {U} ({U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Sea's Claim

Enchant land (Target a land as you cast this. This card enters attached to that land.)
Enchanted land is an Island.

Darksteel Ingot

Indestructible (Effects that say "destroy" don't destroy this artifact.)
{T}: Add one mana of any color.

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

Idyllic Tutor

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.