Boros Signet

Champion's Helm

Equipped creature gets +2/+2.
As long as equipped creature is legendary, it has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Darksteel Hydra

Darksteel Ingot

Indestructible (Effects that say "destroy" don't destroy this artifact.)
{T}: Add one mana of any color.

Dimir Signet

Dreamstone Hedron

{T}: Add {C}{C}{C}.
{3}, {T}, Sacrifice this artifact: Draw three cards.

Fellwar Stone

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

Golgari Signet

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Gruul Signet

Howling Mine

At the beginning of each player's draw step, if this artifact is untapped, that player draws an additional card.

Izzet Signet

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Oblivion Stone

{4}, {T}: Put a fate counter on target permanent.
{5}, {T}, Sacrifice this artifact: Destroy each nonland permanent without a fate counter on it, then remove all fate counters from all permanents.

Orzhov Signet

Prophetic Prism

When this artifact enters, draw a card.
{1}, {T}: Add one mana of any color.

Commander 2011