Untethered Express

Trample
Whenever Untethered Express attacks, put a +1/+1 counter on it.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Painted Bluffs

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Treasure Keeper

When Treasure Keeper dies, reveal cards from the top of your library until you reveal a nonland card with mana value 3 or less. You may cast that card without paying its mana cost. Put all revealed cards not cast this way on the bottom of your library in a random order.

Shimmering Grotto

Holdout Settlement

{T}: Add {C}. ({C} represents colorless mana.)
{T}, Tap an untapped creature you control: Add one mana of any color.

Chief of the Foundry

Other artifact creatures you control get +1/+1.

Skyscanner

Flying
When Skyscanner enters, draw a card.

Evolving Wilds

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

Steel Overseer

{T}: Put a +1/+1 counter on each artifact creature you control.

Voltaic Servant

At the beginning of your end step, untap target artifact.

Warping Wail

({C} represents colorless mana.)
Choose one —
• Exile target creature with power or toughness 1 or less.
• Counter target sorcery spell.
• Create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}."

Spatial Contortion

({C} represents colorless mana.)
Target creature gets +3/-3 until end of turn.

Scalding Cauldron

{3}, {T}, Sacrifice Scalding Cauldron: It deals 3 damage to target creature.

Cathodion

Wastes

Renegade Freighter

Whenever Renegade Freighter attacks, it gets +1/+1 and gains trample until end of turn.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Lesser Masticore

As an additional cost to cast this spell, discard a card.
{4}: Lesser Masticore deals 1 damage to target creature.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)