Arcbound Tracker

Menace
Modular 2 (This creature enters with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
Whenever you cast a spell other than your first spell each turn, put a +1/+1 counter on this creature.

Silverbluff Bridge

This land enters tapped.
Indestructible
{T}: Add {U} or {R}.

Seat of the Synod

Drossforge Bridge

This land enters tapped.
Indestructible
{T}: Add {B} or {R}.

Thoughtcast

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

Mistvault Bridge

This land enters tapped.
Indestructible
{T}: Add {U} or {B}.

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Gearseeker Serpent

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
{5}{U}: This creature can't be blocked this turn.

Frogmite

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

Toxin Analysis

Target creature gains deathtouch and lifelink until end of turn. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Ichor Wellspring

When this artifact enters or is put into a graveyard from the battlefield, draw a card.

Krark-Clan Shaman

Sacrifice an artifact: This creature deals 1 damage to each creature without flying.

Kenku Artificer

Homunculus Servant — When this creature enters, put three +1/+1 counters on up to one target noncreature artifact. That artifact becomes a 0/0 Homunculus artifact creature with flying.

Vault of Whispers

Myr Enforcer

Arcbound Worker

Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Ornithopter

Reckoner's Bargain

As an additional cost to cast this spell, sacrifice an artifact or creature.
You gain life equal to the sacrificed permanent's mana value. Draw two cards.

Refurbished Familiar

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When this creature enters, each opponent discards a card. For each opponent who can't, you draw a card.

Great Furnace

Galvanic Blast

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