Frogmite

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

Darksteel Citadel

Razortide Bridge

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

Ornithopter

Thoughtcast

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

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Ancient Den

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Memnite

Dispatch

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

Esper Sentinel

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

Thought Monitor

Affinity for artifacts
Flying
When Thought Monitor enters the battlefield, draw two cards.

Seat of the Synod

Tempered Steel

Artifact creatures you control get +2/+2.

Sojourner's Companion

Affinity for artifacts
Artifact landcycling {2} ({2}, Discard this card: Search your library for an artifact land card, reveal it, put it into your hand, then shuffle.)