Go for the Throat

Necron Overlord

Relentless March — {X}, {T}, Tap X untapped artifacts you control: Target opponent loses X life.

Buried Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Return target artifact card from your graveyard to your hand.

Barricade Breaker

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
This creature attacks each combat if able.

Lychguard

Guardian Protocols — {3}{B}, Sacrifice this creature: Return all legendary creature cards from your graveyard to your hand.

Szarekh, the Silent King

Flying
My Will Be Done — Whenever Szarekh, the Silent King attacks, mill three cards. You may put an artifact creature card or Vehicle card from among the cards milled this way into your hand.

Gerrard's Hourglass Pendant

Flash
If a player would begin an extra turn, that player skips that turn instead.
{4}, {T}, Exile Gerrard's Hourglass Pendant: Return to the battlefield tapped all artifact, creature, enchantment, and land cards in your graveyard that were put there from the battlefield this turn.

Psychomancer

Flying
Harbinger of Despair — Whenever this creature or another nontoken artifact you control is put into a graveyard from the battlefield or is put into exile from the battlefield, target opponent loses 1 life and you gain 1 life.

Necron Monolith

Flying, indestructible
Eternity Gate — Whenever this Vehicle attacks, mill three cards. For each creature card milled this way, create a 2/2 black Necron Warrior artifact creature token.
Crew 4 (Tap any number of creatures you control with total power 4 or more: This Vehicle becomes an artifact creature until end of turn.)

Illuminor Szeras

Secrets of the Soul — {T}, Sacrifice another creature: Add an amount of {B} equal to the sacrificed creature's mana value.

Flayed One

Lifelink
Flesh Flayer — When this creature enters, mill three cards.

Necron Deathmark

Flash
Synaptic Disintegrator — When this creature enters, destroy up to one target creature and target player mills three cards.

Night Scythe

Flying
Invasion Beams — When this Vehicle enters, create a 2/2 black Necron Warrior artifact creature token.
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.)

Technomancer

When this creature enters, mill three cards, then return any number of artifact creature cards with total mana value 6 or less from your graveyard to the battlefield.

Cloud Key

As this artifact enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Tomb Blade

Flying
Whenever this creature deals combat damage to a player, that player loses life equal to the number of creatures they control unless they sacrifice a creature of their choice.
Unearth {6}{B}{B}

Adaptive Automaton

As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Biotransference

Creatures you control are artifacts in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
Whenever you cast an artifact spell, you lose 1 life and create a 2/2 black Necron Warrior artifact creature token.

Automated Artificer

{T}: Add {C}. Spend this mana only to activate an ability or cast an artifact spell.

Skorpekh Destroyer

Deathtouch
Hyperphase Threshers — Whenever an artifact you control enters, this creature gains first strike until end of turn.

Gate to the Aether

At the beginning of each player's upkeep, that player reveals the top card of their library. If it's an artifact, creature, enchantment, or land card, the player may put it onto the battlefield.

Cover of Darkness

As this enchantment enters, choose a creature type.
Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Hexmark Destroyer

Multi-threat Eliminator — This creature can't be blocked except by six or more creatures.
Unearth {4}{B}{B} ({4}{B}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Trazyn the Infinite

Deathtouch
Prismatic Gallery — As long as Trazyn is on the battlefield, it has all activated abilities of all artifact cards in your graveyard.

Chronomancer

Flying
Atomic Transmutation — {1}, {T}, Sacrifice another artifact: Draw a card.
Unearth {2}{B} ({2}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Lokhust Heavy Destroyer

Flying
Enmitic Exterminator — When this creature enters, each player sacrifices a creature of their choice.
Unearth {5}{B}{B}{B} ({5}{B}{B}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Royal Warden

Phalanx Commander — When this creature enters, create two tapped 2/2 black Necron Warrior artifact creature tokens.
Unearth {3}{B} ({3}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Cryptek

{1}{B}, {T}: Choose another target artifact creature you control. When that creature dies this turn, return it to the battlefield tapped under your control.

Darksteel Forge

Artifacts you control have indestructible. (Effects that say "destroy" don't destroy them. Artifact creatures with indestructible can't be destroyed by damage.)

Plasmancer

Flying
Dynastic Advisor — When this creature enters, search your library for a basic Swamp card, reveal it, put it into your hand, then shuffle.

Cryptothrall

Protector — Other artifact creatures you control have hexproof.

Triarch Praetorian

Flying
Dynastic Codes — When this creature enters from a graveyard, you draw two cards and you lose 2 life.
Unearth {4}{B} ({4}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Sautekh Immortal

Flash
Elite Troops — This creature enters with a +1/+1 counter on it for each creature that died this turn.

Golem's Heart

Whenever a player casts an artifact spell, you may gain 1 life.

Triarch Stalker

Targeting Relay — At the beginning of combat on your turn, choose an opponent.
Creatures attacking the last chosen player have menace.

Skorpekh Lord

Menace
Command Protocols — Other artifact creatures you control get +1/+0 and have menace.
Unearth {2}{B} ({2}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Assassin's Ink

This spell costs {1} less to cast if you control an artifact and {1} less to cast if you control an enchantment.
Destroy target creature or planeswalker.

Beacon of Unrest

Put target artifact or creature card from a graveyard onto the battlefield under your control. Shuffle Beacon of Unrest into its owner's library.

Their Number Is Legion

Create X tapped 2/2 black Necron Warrior artifact creature tokens, then you gain life equal to the number of artifacts you control. Exile Their Number Is Legion.
You may cast this card from your graveyard.

Cybermen Squadron

Nonlegendary artifact creatures you control have myriad. (Whenever a creature with myriad 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.)