Arcane Signet

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

Rakdos Signet

Thought Monitor

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

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Sol Ring

Dimir Signet

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. Talisman of Creativity deals 1 damage to you.

Orzhov Signet

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. Talisman of Progress deals 1 damage to you.

Candlekeep Sage

Commander creatures you own have "When this creature enters or leaves the battlefield, draw a card."

Wernog, Rider's Chaplain

When Wernog, Rider's Chaplain enters or leaves the battlefield, each opponent may investigate. Each opponent who doesn't loses 1 life. You investigate X times, where X is one plus the number of opponents who investigated this way.
Friends forever (You can have two commanders if both have friends forever.)

Talisman of Hierarchy

{T}: Add {C}.
{T}: Add {W} or {B}. Talisman of Hierarchy deals 1 damage to you.

Shimmer Dragon

Flying
As long as you control four or more artifacts, Shimmer Dragon has hexproof.
Tap two untapped artifacts you control: Draw a card.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Izzet Signet

Extraordinary Journey

When Extraordinary Journey enters, exile up to X target creatures. For each of those cards, its owner may play it for as long as it remains exiled.
Whenever one or more nontoken creatures enter, if one or more of them entered from exile or was cast from exile, you draw a card. This ability triggers only once each turn.

Bjorna, Nightfall Alchemist

{T}, Sacrifice an artifact: Bjorna, Nightfall Alchemist deals 1 damage to target creature. Goad that creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Friends forever (You can have two commanders if both have friends forever.)