Seat of the Synod

Island

Chromatic Star

{1}, {T}, Sacrifice Chromatic Star: Add one mana of any color.
When Chromatic Star is put into a graveyard from the battlefield, draw a card.

Silverbluff Bridge

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

Temur Battle Rage

Target creature gains double strike until end of turn.
Ferocious — That creature also gains trample until end of turn if you control a creature with power 4 or greater.

Darksteel Citadel

Gearseeker Serpent

This spell costs {1} less to cast for each artifact you control.
{5}{U}: Gearseeker Serpent can't be blocked this turn.

Mountain

Frogmite

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)

Atog

Sacrifice an artifact: Atog gets +2/+2 until end of turn.

Thoughtcast

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Draw two cards.

Ichor Wellspring

When Ichor Wellspring enters or is put into a graveyard from the battlefield, draw a card.

Terminate

Destroy target creature. It can't be regenerated.

Vault of Whispers

Mistvault Bridge

Mistvault Bridge enters tapped.
Indestructible
{T}: Add {U} or {B}.

Ornithopter

Galvanic Blast

Galvanic Blast deals 2 damage to any target.
Metalcraft — Galvanic Blast deals 4 damage instead if you control three or more artifacts.

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Sojourner's Companion

Affinity for artifacts
Artifact landcycling {2} ({2}, Discard this card: Search your library for an artifact land card, reveal it, put it into your hand, then shuffle.)

Great Furnace

Witching Well

When Witching Well enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)
{3}{U}, Sacrifice Witching Well: Draw two cards.