Sea of Clouds

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

Glacial Fortress

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

Mystic Gate

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

Snow-Covered Plains

Reliquary Tower

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

Mistgate Pathway

Hengegate Pathway

Hengegate Pathway // Mistgate Pathway

Prairie Stream

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

Sol Ring

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. Talisman of Progress deals 1 damage to you.

Fabled Passage

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Deserted Beach

Deserted Beach enters the battlefield tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters the battlefield tapped unless you control three or more other Islands.
When Mystic Sanctuary enters the battlefield untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Azorius Signet

Adarkar Wastes

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

Arcane Signet

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

Snow-Covered Island

Eiganjo, Seat of the Empire

{T}: Add {W}.
Channel — {2}{W}, Discard Eiganjo, Seat of the Empire: It deals 4 damage to target attacking or blocking creature. This ability costs {1} less to activate for each legendary creature you control.

Arcane Lighthouse

{T}: Add {C}.
{1}, {T}: Until end of turn, creatures your opponents control lose hexproof and shroud and can't have hexproof or shroud.

Command Tower

Seachrome Coast

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

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Hylda of the Icy Crown

Whenever you tap an untapped creature an opponent controls, you may pay {1}. When you do, choose one —
• Create a 4/4 white and blue Elemental creature token.
• Put a +1/+1 counter on each creature you control.
• Scry 2, then draw a card.

Forbidden Orchard

{T}: Add one mana of any color.
Whenever you tap Forbidden Orchard for mana, target opponent creates a 1/1 colorless Spirit creature token.

Hallowed Fountain

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