Fellwar Stone

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

Sol Ring

Arcane Signet

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

Talisman of Creativity

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

Izzet Signet

Dimir Signet

Nekusar, the Mindrazer

At the beginning of each player's draw step, that player draws an additional card.
Whenever an opponent draws a card, Nekusar, the Mindrazer deals 1 damage to that player.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Talisman of Dominance

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

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.