Mountain

Arcane Signet

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

Rugged Prairie

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

Ancient Den

Pillarverge Pathway

Needleverge Pathway

Needleverge Pathway // Pillarverge Pathway

Slayers' Stronghold

{T}: Add {C}.
{R}{W}, {T}: Target creature gets +2/+0 and gains vigilance and haste until end of turn.

Great Furnace

Cursed Mirror

{T}: Add {R}.
As Cursed Mirror enters the battlefield, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

Sol Ring

Inspiring Vantage

Inspiring Vantage enters the battlefield tapped unless you control two or fewer other lands.
{T}: Add {R} or {W}.

Spectator Seating

Spectator Seating enters the battlefield tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Sacred Foundry

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

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Reliquary Tower

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

Buried Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Buried Ruin: Return target artifact card from your graveyard to your hand.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Furycalm Snarl

As Furycalm Snarl enters the battlefield, you may reveal a Mountain or Plains card from your hand. If you don't, Furycalm Snarl enters the battlefield tapped.
{T}: Add {R} or {W}.

Fellwar Stone

Clifftop Retreat

Clifftop Retreat enters the battlefield tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Osgir, the Reconstructor

Vigilance
{1}, Sacrifice an artifact: Target creature you control gets +2/+0 until end of turn.
{X}, {T}, Exile an artifact card with mana value X from your graveyard: Create two tokens that are copies of the exiled card. Activate only as a sorcery.

Command Tower

Mines of Moria

Mines of Moria enters the battlefield tapped unless you control a legendary creature.
{T}: Add {R}.
{3}{R}, {T}, Exile three cards from your graveyard: Create two Treasure tokens.

Glittering Stockpile

{T}: Add {R}. Put a stash counter on Glittering Stockpile.
{T}, Sacrifice Glittering Stockpile: Add X mana of any one color, where X is the number of stash counters on Glittering Stockpile.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Sunhome, Fortress of the Legion

{T}: Add {C}.
{2}{R}{W}, {T}: Target creature gains double strike until end of turn.

Boros Signet

Thought Vessel

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Temple of Triumph

Temple of Triumph enters the battlefield tapped.
When Temple of Triumph enters the battlefield, scry 1.
{T}: Add {R} or {W}.

Plains

Sundown Pass

Sundown Pass enters the battlefield tapped unless you control two or more other lands.
{T}: Add {R} or {W}.

Talisman of Conviction

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