Fellwar Stone

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

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Izzet Signet

Mountain

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Talisman of Creativity

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

Arcane Signet

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

Sol Ring

Ignite the Future

Exile the top three cards of your library. Until the end of your next turn, you may play those cards. If this spell was cast from a graveyard, you may play cards this way without paying their mana costs.
Flashback {7}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Cursed Mirror

{T}: Add {R}.
As Cursed Mirror enters, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

Mizzix, Replica Rider

Flying
Whenever you cast a spell from anywhere other than your hand, you may pay {1}{U/R}. If you do, copy that spell and you may choose new targets for the copy. If the copy is a permanent spell, it gains haste and "At the beginning of your end step, sacrifice this permanent." (A copy of a permanent spell becomes a token.)

Expressive Iteration

Look at the top three cards of your library. Put one of them into your hand, put one of them on the bottom of your library, and exile one of them. You may play the exiled card this turn.

Wild-Magic Sorcerer

The first spell you cast from exile each turn has cascade. (When you cast your first spell from exile, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)