Razortide Bridge

Razortide Bridge enters tapped.
Indestructible
{T}: Add {W} or {U}.

The Golden-Gear Colossus

Vigilance, trample
Whenever The Golden-Gear Colossus enters or attacks, transform up to one other target double-faced artifact you control. Create two 1/1 colorless Gnome artifact creature tokens.

Tetzin, Gnome Champion

Whenever Tetzin or another double-faced artifact you control enters, mill three cards. You may put an artifact card from among them into your hand.
Craft with six artifacts {4} ({4}, Exile this artifact, Exile the six from among other permanents you control and/or cards from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Tetzin, Gnome Champion // The Golden-Gear Colossus

Izzet Signet

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Battlefield Forge

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

Optimus Prime, Autobot Leader

Living metal (During your turn, this Vehicle is also a creature.)
Trample
Whenever you attack, bolster 2. The chosen creature gains trample until end of turn. When that creature deals combat damage to a player this turn, convert Optimus Prime.

Optimus Prime, Hero

More Than Meets the Eye {2}{U}{R}{W} (You may cast this card converted for {2}{U}{R}{W}.)
At the beginning of each end step, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)
When Optimus Prime dies, return it to the battlefield converted under its owner's control.

Optimus Prime, Hero // Optimus Prime, Autobot Leader

Jhoira's Familiar

Flying
Historic spells you cast cost {1} less to cast. (Artifacts, legendaries, and Sagas are historic.)

Great Furnace

Adarkar Wastes

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

Spectator Seating

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

Plains

Seat of the Synod

Sandswirl Wanderglyph

Flying
Whenever an opponent casts a spell during their turn, they can't attack you or planeswalkers you control this turn.
Each opponent who attacked you or a planeswalker you control this turn can't cast spells.

Unstable Glyphbridge

When Unstable Glyphbridge enters, if you cast it, for each player, choose a creature with power 2 or less that player controls. Then destroy all creatures except creatures chosen this way.
Craft with artifact {3}{W}{W} ({3}{W}{W}, Exile this artifact, Exile another artifact you control or an artifact card from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Unstable Glyphbridge // Sandswirl Wanderglyph

Island

Sol Ring

Ancient Den

Mystic Monastery

Mystic Monastery enters tapped.
{T}: Add {U}, {R}, or {W}.

Rustvale Bridge

Rustvale Bridge enters tapped.
Indestructible
{T}: Add {R} or {W}.

Mountain

Silverbluff Bridge

Silverbluff Bridge enters tapped.
Indestructible
{T}: Add {U} or {R}.

Arcane Signet

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

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Sea of Clouds

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

Boros Signet

Anim Pakal, Thousandth Moon

Whenever you attack with one or more non-Gnome creatures, put a +1/+1 counter on Anim Pakal, then create X 1/1 colorless Gnome artifact creature tokens that are tapped and attacking, where X is the number of +1/+1 counters on Anim Pakal.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}