Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Sky Diamond

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Sol Ring

Jin-Gitaxias, Progress Tyrant

Whenever you cast an artifact, instant, or sorcery spell, copy that spell. You may choose new targets for the copy. This ability triggers only once each turn. (A copy of a permanent spell becomes a token.)
Whenever an opponent casts an artifact, instant, or sorcery spell, counter that spell. This ability triggers only once each turn.

Thran Dynamo

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.