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.

Thalia, Guardian of Thraben

First strike
Noncreature spells cost {1} more to cast.

Drannith Magistrate

Your opponents can't cast spells from anywhere other than their hands.

Elesh Norn, Mother of Machines

Vigilance
If a permanent entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Permanents entering don't cause abilities of permanents your opponents control to trigger.