Command Tower

{T}: Add one mana of any color in your commander's color identity.

Riptide Laboratory

{T}: Add {C}.
{1}{U}, {T}: Return target Wizard you control to its owner's hand.

Kor Haven

{T}: Add {C}.
{1}{W}, {T}: Prevent all combat damage that would be dealt by target attacking creature this turn.

Mirrorpool

Mirrorpool enters tapped.
{T}: Add {C}.
{2}{C}, {T}, Sacrifice Mirrorpool: Copy target instant or sorcery spell you control. You may choose new targets for the copy.
{4}{C}, {T}, Sacrifice Mirrorpool: Create a token that's a copy of target creature you control.

Irrigated Farmland

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

Snow-Covered Plains

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Horizon Stone

If you would lose unspent mana, that mana becomes colorless instead.

Rasputin Dreamweaver

Rasputin Dreamweaver enters with seven dream counters on it.
Remove a dream counter from Rasputin: Add {C}.
Remove a dream counter from Rasputin: Prevent the next 1 damage that would be dealt to Rasputin this turn.
At the beginning of your upkeep, if Rasputin started the turn untapped, put a dream counter on it.
Rasputin can't have more than seven dream counters on it.

Tundra

Scavenger Grounds

{T}: Add {C}.
{2}, {T}, Sacrifice a Desert: Exile all graveyards.

Prahv, Spires of Order

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

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

Homeward Path

{T}: Add {C}.
{T}: Each player gains control of all creatures they own.

Snow-Covered Island

Arch of Orazca

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
{T}: Add {C}.
{5}, {T}: Draw a card. Activate only if you have the city's blessing.

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Hallowed Fountain

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

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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}.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Mystifying Maze

{T}: Add {C}.
{4}, {T}: Exile target attacking creature an opponent controls. At the beginning of the next end step, return it to the battlefield tapped under its owner's control.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.