Silverbluff Bridge

Silverbluff Bridge enters tapped.
Indestructible
{T}: Add {U} or {R}.

Seat of the Synod

As an additional cost to cast this spell, sacrifice an artifact.
Create three 1/1 red Goblin creature tokens.

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

Galvanic Blast deals 2 damage to any target.
Metalcraft — Galvanic Blast deals 4 damage instead if you control three or more artifacts.

As an additional cost to cast this spell, sacrifice a Goblin.
Goblin Grenade deals 5 damage to any target.

As an additional cost to cast this spell, sacrifice an artifact or creature.
Artillerize deals 5 damage to any target.