Fellwar Stone

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

Rakdos Signet

Garna, the Bloodflame

Flash
When Garna, the Bloodflame enters, return to your hand all creature cards in your graveyard that were put there from anywhere this turn.
Other creatures you control have haste.

Arcane Signet

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

Sol Ring

Talisman of Indulgence

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