Nimbus Maze

{T}: Add {C}.
{T}: Add {W}. Activate only if you control an Island.
{T}: Add {U}. Activate only if you control a Plains.

Irrigated Farmland

({T}: Add {W} or {U}.)
Irrigated Farmland enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Port Town

As Port Town enters, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters tapped.
{T}: Add {W} or {U}.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Ojutai Monument

{T}: Add {W} or {U}.
{4}{W}{U}: Ojutai Monument becomes a 4/4 white and blue Dragon artifact creature with flying until end of turn.

Ephara, God of the Polis

Indestructible
As long as your devotion to white and blue is less than seven, Ephara isn't a creature.
At the beginning of each upkeep, if you had another creature enter the battlefield under your control last turn, draw a card.

Temple of Enlightenment

Temple of Enlightenment enters tapped.
When Temple of Enlightenment enters, scry 1.
{T}: Add {W} or {U}.

Azorius Cluestone

{T}: Add {W} or {U}.
{W}{U}, {T}, Sacrifice Azorius Cluestone: Draw a card.

Moorland Haunt

{T}: Add {C}.
{W}{U}, {T}, Exile a creature card from your graveyard: Create a 1/1 white Spirit creature token with flying.

Seachrome Coast

Seachrome Coast enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Fieldmist Borderpost

You may pay {1} and return a basic land you control to its owner's hand rather than pay this spell's mana cost.
Fieldmist Borderpost enters tapped.
{T}: Add {W} or {U}.

Mystic Gate

{T}: Add {C}.
{W/U}, {T}: Add {W}{W}, {W}{U}, or {U}{U}.

Wanderwine Hub

As Wanderwine Hub enters, you may reveal a Merfolk card from your hand. If you don't, Wanderwine Hub enters tapped.
{T}: Add {W} or {U}.

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Calciform Pools

{T}: Add {C}.
{1}, {T}: Put a storage counter on Calciform Pools.
{1}, Remove X storage counters from Calciform Pools: Add X mana in any combination of {W} and/or {U}.

Boreal Shelf

Boreal Shelf enters tapped.
{T}: Add {W} or {U}.

Prahv, Spires of Order

{T}: Add {C}.
{4}{W}{U}, {T}: Prevent all damage a source of your choice would deal this turn.

Cloudcrest Lake

{T}: Add {C}.
{T}: Add {W} or {U}. Cloudcrest Lake doesn't untap during your next untap step.

Coastal Tower

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

Seaside Haven

{T}: Add {C}.
{W}{U}, {T}, Sacrifice a Bird: Draw a card.

Skycloud Egg

{2}, {T}, Sacrifice Skycloud Egg: Add {W}{U}. Draw a card.

Skycloud Expanse

Seashell Cameo

Thalakos Lowlands

{T}: Add {C}.
{T}: Add {W} or {U}. Thalakos Lowlands doesn't untap during your next untap step.

Land Cap

Land Cap doesn't untap during your untap step if it has a depletion counter on it.
At the beginning of your upkeep, remove a depletion counter from Land Cap.
{T}: Add {W} or {U}. Put a depletion counter on Land Cap.

Tundra

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Sejiri Refuge

Sejiri Refuge enters tapped.
When Sejiri Refuge enters, you gain 1 life.
{T}: Add {W} or {U}.

Meandering River

Meandering River enters tapped.
{T}: Add {W} or {U}.

Celestial Colonnade

Celestial Colonnade enters tapped.
{T}: Add {W} or {U}.
{3}{W}{U}: Until end of turn, Celestial Colonnade becomes a 4/4 white and blue Elemental creature with flying and vigilance. It's still a land.

Azorius Guildgate

Azorius Guildgate enters tapped.
{T}: Add {W} or {U}.

Azorius Signet

Azorius Keyrune

{T}: Add {W} or {U}.
{W}{U}: Azorius Keyrune becomes a 2/2 white and blue Bird artifact creature with flying until end of turn.

Glacial Fortress

Glacial Fortress enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Tranquil Cove

Tranquil Cove enters tapped.
When Tranquil Cove enters, you gain 1 life.
{T}: Add {W} or {U}.

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Azorius Locket

{T}: Add {W} or {U}.
{W/U}{W/U}{W/U}{W/U}, {T}, Sacrifice Azorius Locket: Draw two cards.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.