Hedron Crawler

{T}: Add {C}. ({C} represents colorless mana.)

Artificer's Epiphany

Draw two cards. If you control no artifacts, discard a card.

Prism Ring

As Prism Ring enters, choose a color.
Whenever you cast a spell of the chosen color, you gain 1 life.

Thopter Engineer

When Thopter Engineer enters, create a 1/1 colorless Thopter artifact creature token with flying.
Artifact creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Maverick Thopterist

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
When Maverick Thopterist enters, create two 1/1 colorless Thopter artifact creature tokens with flying.

Ghirapur Gearcrafter

When Ghirapur Gearcrafter enters, create a 1/1 colorless Thopter artifact creature token with flying. (A creature with flying can't be blocked except by creatures with flying or reach.)

Pia and Kiran Nalaar

When Pia and Kiran Nalaar enters, create two 1/1 colorless Thopter artifact creature tokens with flying.
{2}{R}, Sacrifice an artifact: Pia and Kiran Nalaar deals 2 damage to any target.

Diamond Knight

Vigilance (Attacking doesn't cause this creature to tap.)
As Diamond Knight enters, choose a color.
Whenever you cast a spell of the chosen color, put a +1/+1 counter on Diamond Knight.

Portal of Sanctuary

{1}, {T}: Return target creature you control and each Aura attached to it to their owners' hands. Activate only during your turn.

Whirler Virtuoso

When Whirler Virtuoso enters, you get {E}{E}{E} (three energy counters).
Pay {E}{E}{E}: Create a 1/1 colorless Thopter artifact creature token with flying.

Guardian Automaton

When Guardian Automaton dies, you gain 3 life.

Runed Servitor

When Runed Servitor dies, each player draws a card.

Efficient Construction

Whenever you cast an artifact spell, create a 1/1 colorless Thopter artifact creature token with flying.

Prismite

Whirler Rogue

When Whirler Rogue enters, create two 1/1 colorless Thopter artifact creature tokens with flying.
Tap two untapped artifacts you control: Target creature can't be blocked this turn.

Alchemist's Vial

When Alchemist's Vial enters, draw a card.
{1}, {T}, Sacrifice Alchemist's Vial: Target creature can't attack or block this turn.

Foundry Assembler

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Bonded Construct

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Aspiring Aeronaut

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Aspiring Aeronaut enters, create a 1/1 colorless Thopter artifact creature token with flying.

Reclusive Artificer

Haste (This creature can attack and {T} as soon as it comes under your control.)
When Reclusive Artificer enters, you may have it deal damage to target creature equal to the number of artifacts you control.

Mountain

Separatist Voidmage

When Separatist Voidmage enters, you may return target creature to its owner's hand.