Coveted Jewel

When Coveted Jewel enters, draw three cards.
{T}: Add three mana of any one color.
Whenever one or more creatures an opponent controls attack you and aren't blocked, that player draws three cards and gains control of Coveted Jewel. Untap it.

Sky Diamond

Sol Ring

Twiddle

You may tap or untap target artifact, creature, or land.

Arcane Signet

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

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Unsummon

Return target creature to its owner's hand.

Mind Stone

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

Island

Orvar, the All-Form

Changeling
Whenever you cast an instant or sorcery spell, if it targets one or more other permanents you control, create a token that's a copy of one of those permanents.
When a spell or ability an opponent controls causes you to discard this card, create a token that's a copy of target permanent.

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Hidden Strings

You may tap or untap target permanent, then you may tap or untap another target permanent.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Boomerang

Return target permanent to its owner's hand.

Toils of Night and Day

You may tap or untap target permanent, then you may tap or untap another target permanent.