Chalice of the Void

This artifact enters with X charge counters on it.
Whenever a player casts a spell with mana value equal to the number of charge counters on this artifact, counter that spell.

Eiganjo, Seat of the Empire

{T}: Add {W}.
Channel — {2}{W}, Discard this card: It deals 4 damage to target attacking or blocking creature. This ability costs {1} less to activate for each legendary creature you control.

Pithing Needle

As this artifact enters, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — This Saga gains "{T}: Add {C}."
II — This Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This token gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Portable Hole

When this artifact enters, exile target nonland permanent an opponent controls with mana value 2 or less until this artifact leaves the battlefield.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Thought Monitor

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When this creature enters, draw two cards.

Nettlecyst

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each artifact and/or enchantment you control.
Equip {2}

Flooded Strand

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Reprieve

Return target spell to its owner's hand.
Draw a card.

Ingenious Smith

When this creature 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 a random order.
Whenever one or more artifacts you control enter, put a +1/+1 counter on this creature. This ability triggers only once each turn.

Memnite

Relic of Progenitus

{T}: Target player exiles a card from their graveyard.
{1}, Exile this artifact: Exile all graveyards. Draw a card.

Meddling Mage

As this creature enters, choose a nonland card name.
Spells with the chosen name can't be cast.

Sanctifier en-Vec

Protection from black and from red
When this creature enters, exile all cards that are black or red from all graveyards.
If a black or red permanent, spell, or card not on the battlefield would be put into a graveyard, exile it instead.

Metallic Rebuke

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Counter target spell unless its controller pays {3}.

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Teferi, Time Raveler

Each opponent can cast spells only any time they could cast a sorcery.
+1: Until your next turn, you may cast sorcery spells as though they had flash.
−3: Return up to one target artifact, creature, or enchantment to its owner's hand. Draw a card.

Urza, Lord High Artificer

When Urza enters, create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."
Tap an untapped artifact you control: Add {U}.
{5}: Shuffle your library, then exile the top card. Until end of turn, you may play that card without paying its mana cost.

Simulacrum Synthesizer

When this artifact enters, scry 2.
Whenever another artifact you control with mana value 3 or greater enters, create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."

Dispatch

Tap target creature.
Metalcraft — If you control three or more artifacts, exile that creature.

Razortide Bridge

This land enters tapped.
Indestructible
{T}: Add {W} or {U}.

Darksteel Citadel

Thoughtcast

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Draw two cards.

Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is this creature's power.

Mystical Dispute

This spell costs {2} less to cast if it targets a blue spell.
Counter target spell unless its controller pays {3}.

Seachrome Coast

This land enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.