Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Magosi, the Waterveil

Magosi, the Waterveil enters tapped.
{T}: Add {U}.
{U}, {T}: Put an eon counter on Magosi, the Waterveil. Skip your next turn.
{T}, Remove an eon counter from Magosi, the Waterveil and return it to its owner's hand: Take an extra turn after this one.

Inexorable Tide

Whenever you cast a spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Contagion Engine

When Contagion Engine enters, put a -1/-1 counter on each creature target player controls.
{4}, {T}: Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Rings of Brighthearth

Whenever you activate an ability, if it isn't a mana ability, you may pay {2}. If you do, copy that ability. You may choose new targets for the copy.

Expedition Map

{2}, {T}, Sacrifice this artifact: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Tezzeret the Seeker

+1: Untap up to two target artifacts.
−X: Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.
−5: Artifacts you control become artifact creatures with base power and toughness 5/5 until end of turn.

Inventors' Fair

At the beginning of your upkeep, if you control three or more artifacts, you gain 1 life.
{T}: Add {C}.
{4}, {T}, Sacrifice Inventors' Fair: Search your library for an artifact card, reveal it, put it into your hand, then shuffle. Activate only if you control three or more artifacts.

Whir of Invention

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Echoing Deeps

You may have Echoing Deeps enter tapped as a copy of any land card in a graveyard, except it's a Cave in addition to its other types.
{T}: Add {C}.

Goldberry, River-Daughter

{T}: Move a counter of each kind not on Goldberry, River-Daughter from another target permanent you control onto Goldberry.
{U}, {T}: Move one or more counters from Goldberry onto another target permanent you control. If you do, draw a card.

Radstorm

Storm (When you cast this spell, copy it for each spell cast before it this turn.)
Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Flux Channeler

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Reshape

As an additional cost to cast this spell, sacrifice an artifact.
Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.

Adric, Mathematical Genius

{2}{U}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy.
Ultimate Sacrifice — {1}{U}, Sacrifice Adric: Counter target activated or triggered ability.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Thespian's Stage

{T}: Add {C}.
{2}, {T}: Thespian's Stage becomes a copy of target land, except it has this ability.

Urza's Cave

{T}: Add {C}.
{3}, {T}, Sacrifice Urza's Cave: Search your library for a land card, put it onto the battlefield tapped, then shuffle.

Deepglow Skate

When Deepglow Skate enters, double the number of each kind of counter on any number of target permanents.

Fuel for the Cause

Counter target spell, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Lithoform Engine

{2}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy.
{3}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.
{4}, {T}: Copy target permanent spell you control. (The copy becomes a token.)

Mesmerizing Dose

Enchant creature
When Mesmerizing Dose enters, tap enchanted creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Enchanted creature doesn't untap during its controller's untap step.

Nesting Grounds

{T}: Add {C}.
{1}, {T}: Move a counter from target permanent you control onto another target permanent. Activate only as a sorcery.

Vesuva

You may have Vesuva enter tapped as a copy of any land on the battlefield.

Contentious Plan

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Draw a card.

Staff of Compleation

{T}, Pay 1 life: Destroy target permanent you own.
{T}, Pay 2 life: Add one mana of any color.
{T}, Pay 3 life: Proliferate.
{T}, Pay 4 life: Draw a card.
{5}: Untap Staff of Compleation.

Contagion Clasp

When Contagion Clasp enters, put a -1/-1 counter on target creature.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Steady Progress

Artificer's Intuition

{U}, Discard an artifact card: Search your library for an artifact card with mana value 1 or less, reveal it, put it into your hand, then shuffle.

Arcum Dagsson

{T}: Target artifact creature's controller sacrifices it. That player may search their library for a noncreature artifact card, put it onto the battlefield, then shuffle.

Tolaria West

Tolaria West enters tapped.
{T}: Add {U}.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with mana value 0, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Trinket Mage

When Trinket Mage enters, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.