Izzet Signet

Worldwalker Helm

If you would create one or more artifact tokens, instead create those tokens plus an additional Map token. (It's an artifact with "{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")
{1}{U}, {T}: Create a token that's a copy of target artifact token you control.

The Master, Gallifrey's End

Make Them Pay — Whenever a nontoken artifact creature you control dies, you may exile it. If you do, choose an opponent with the most life among your opponents. That player faces a villainous choice — They lose 4 life, or you create a token that's a copy of that card.

Dimir Signet

Brudiclad, Telchor Engineer

Creature tokens you control have haste.
At the beginning of combat on your turn, create a 2/1 blue Phyrexian Myr artifact creature token. Then you may choose a token you control. If you do, each other token you control becomes a copy of that token.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Sol Ring

Mirrorworks

Whenever another nontoken artifact you control enters, you may pay {2}. If you do, create a token that's a copy of that artifact.

Vanguard Suppressor

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Flying
Suppressing Fire — Whenever Vanguard Suppressor deals combat damage to a player, draw a card.

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Auton Soldier

You may have Auton Soldier enter as a copy of any creature on the battlefield, except it isn't legendary, is an artifact in addition to its other types, and has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. Talisman of Creativity deals 1 damage to you.

Ashad, the Lone Cyberman

The first nonlegendary artifact spell you cast each turn has casualty 2. (As you cast it, you may sacrifice a creature with power 2 or greater. When you do, copy it. A copy of an artifact spell becomes a token.)
Whenever you sacrifice another creature, put a +1/+1 counter on Ashad, the Lone Cyberman.

Blade of Shared Souls

For Mirrodin! (When this Equipment enters, create a 2/2 red Rebel creature token, then attach this to it.)
Whenever Blade of Shared Souls becomes attached to a creature, for as long as Blade of Shared Souls remains attached to it, you may have that creature become a copy of another target creature you control.
Equip {2}

Talisman of Indulgence

{T}: Add {C}.
{T}: Add {B} or {R}. Talisman of Indulgence deals 1 damage to you.

Rakdos Signet

Machine God's Effigy

You may have Machine God's Effigy enter as a copy of any creature on the battlefield, except it's an artifact and it has "{T}: Add {U}." (It's not a creature.)
{T}: Add {U}.

Esoteric Duplicator

Whenever you sacrifice Esoteric Duplicator or another artifact, you may pay {2}. If you do, at the beginning of the next end step, create a token that's a copy of that artifact.
{2}, Sacrifice Esoteric Duplicator: Draw a card.

Mechanized Production

Enchant artifact you control
At the beginning of your upkeep, create a token that's a copy of enchanted artifact. Then if you control eight or more artifacts with the same name as one another, you win the game.

Sicarian Infiltrator

Flash
Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Benediction of the Omnissiah — When Sicarian Infiltrator enters, draw a card.