Have

Ornithopter

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

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}.

Kenku Artificer

Homunculus Servant — When Kenku Artificer enters, put three +1/+1 counters on up to one target noncreature artifact. That artifact becomes a 0/0 Homunculus artifact creature with flying.

Myr Enforcer

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

Springleaf Drum

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

Thraben Inspector

When Thraben Inspector enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Gingerbrute

Haste (This creature can attack and {T} as soon as it comes under your control.)
{1}: Gingerbrute can't be blocked this turn except by creatures with haste.
{2}, {T}, Sacrifice Gingerbrute: You gain 3 life.

Holy Day

Prevent all combat damage that would be dealt this turn.

Disenchant

Hydroblast

Choose one —
• Counter target spell if it's red.
• Destroy target permanent if it's red.

Razortide Bridge

Razortide Bridge enters tapped.
Indestructible
{T}: Add {W} or {U}.

All That Glitters

Enchant creature
Enchanted creature gets +1/+1 for each artifact and/or enchantment you control.

Seat of the Synod

Thoughtcast

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

Aether Spellbomb

{U}, Sacrifice Aether Spellbomb: Return target creature to its owner's hand.
{1}, Sacrifice Aether Spellbomb: Draw a card.

Darksteel Citadel

Of One Mind

This spell costs {2} less to cast if you control a Human creature and a non-Human creature.
Draw two cards.

Island

Annul

Counter target artifact or enchantment spell.

Frogmite

Loran's Escape

Target artifact or creature gains hexproof and indestructible until end of turn. Scry 1.

Moon-Circuit Hacker

Ninjutsu {U} ({U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Moon-Circuit Hacker deals combat damage to a player, you may draw a card. If you do, discard a card unless Moon-Circuit Hacker entered this turn.