Seat of the Synod

Darksteel Citadel

Island

Master Transmuter

{U}, {T}, Return an artifact you control to its owner's hand: You may put an artifact card from your hand onto the battlefield.

Vault of Whispers

Sludge Strider

Whenever another artifact enters the battlefield under your control or another artifact you control leaves the battlefield, you may pay {1}. If you do, target player loses 1 life and you gain 1 life.

Cranial Plating

Equipped creature gets +1/+0 for each artifact you control.
{B}{B}: Attach Cranial Plating to target creature you control.
Equip {1}

Baleful Strix

Flying, deathtouch
When Baleful Strix enters the battlefield, draw a card.

Etherium Sculptor

Artifact spells you cast cost {1} less to cast.

Time Sieve

{T}, Sacrifice five artifacts: Take an extra turn after this one.