Modular Monstrosity

Whenever an opponent casts a spell, you have five seconds to choose a keyword you haven't chosen for a card named Modular Monstrosity today that's been printed on a creature card. If you do, Modular Monstrosity gains that ability. Otherwise, Modular Monstrosity loses all keyword abilities.

Arcbound Prototype

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.)

Gearsmith Prodigy

Gearsmith Prodigy gets +1/+0 as long as you control an artifact.

Glint-Nest Crane

Flying
When Glint-Nest Crane enters, look at the top four cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Darksteel Citadel

Tezzeret's Gatebreaker

When Tezzeret's Gatebreaker enters, look at the top five cards of your library. You may reveal a blue or artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
{5}{U}, {T}, Sacrifice Tezzeret's Gatebreaker: Creatures you control can't be blocked this turn.

Self-Assembler

When Self-Assembler enters, you may search your library for an Assembly-Worker creature card, reveal it, put it into your hand, then shuffle.

Zephyr Boots

Equipped creature has flying.
Whenever equipped creature deals combat damage to a player, draw a card, then discard a card.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Zabaz, the Glimmerwasp

Modular 1
If a modular triggered ability would put one or more +1/+1 counters on a creature you control, that many plus one +1/+1 counters are put on it instead.
{R}: Destroy target artifact you control.
{W}: Zabaz, the Glimmerwasp gains flying until end of turn.

Steel Overseer

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

Temporal Machinations

Return target creature to its owner's hand. If you control an artifact, draw a card.

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.)

Shrine of the Forsaken Gods

{T}: Add {C}.
{T}: Add {C}{C}. Spend this mana only to cast colorless spells. Activate only if you control seven or more lands.

Jhoira's Familiar

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

Zahid, Djinn of the Lamp

You may pay {3}{U} and tap an untapped artifact you control rather than pay this spell's mana cost.
Flying

Island

Azorius Cluestone

{T}: Add {W} or {U}.
{W}{U}, {T}, Sacrifice Azorius Cluestone: Draw a card.

Obelisk of Urd

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As Obelisk of Urd enters, choose a creature type.
Creatures you control of the chosen type get +2/+2.

Skilled Animator

When Skilled Animator enters, target artifact you control becomes an artifact creature with base power and toughness 5/5 for as long as Skilled Animator remains on the battlefield.

Thirst for Knowledge

Draw three cards. Then discard two cards unless you discard an artifact card.

Workshop Assistant

When Workshop Assistant dies, return another target artifact card from your graveyard to your hand.

Radiant Fountain

When Radiant Fountain enters, you gain 2 life.
{T}: Add {C}.

Plains

Skyscanner

Flying
When Skyscanner enters, draw a card.

Mishra's Self-Replicator

Whenever you cast a historic spell, you may pay {1}. If you do, create a token that's a copy of Mishra's Self-Replicator. (Artifacts, legendaries, and Sagas are historic.)

Arcbound Overseer

At the beginning of your upkeep, put a +1/+1 counter on each creature you control with modular.
Modular 6 (This creature enters with six +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)