Arcane Signet

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

Niblis of the Breath

Flying
{U}, {T}: You may tap or untap target creature.

Teardrop Kami

Sacrifice Teardrop Kami: You may tap or untap target creature.

Refocus

Xavier Sal, Infested Captain

{T}, Remove a counter from another permanent you control: Populate. Activate only as a sorcery. (Create a token that's a copy of a creature token you control.)
{T}, Sacrifice another creature: Proliferate. Activate only as a sorcery. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Puppet Strings

{2}, {T}: You may tap or untap target creature.

Counterspell

Staff of Domination

{1}: Untap Staff of Domination.
{2}, {T}: You gain 1 life.
{3}, {T}: Untap target creature.
{4}, {T}: Tap target creature.
{5}, {T}: Draw a card.

Ornamental Courage

Untap target creature. It gets +1/+3 until end of turn.

Scryb Ranger

Flash
Flying, protection from blue
Return a Forest you control to its owner's hand: Untap target creature. Activate only once each turn.

Stonybrook Angler

{1}{U}, {T}: You may tap or untap target creature.

Magewright's Stone

{1}, {T}: Untap target creature that has an activated ability with {T} in its cost.

Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Thousand-Year Elixir

You may activate abilities of creatures you control as though those creatures had haste.
{1}, {T}: Untap target creature.

Jandor's Saddlebags

Retreat to Coralhelm

Landfall — Whenever a land you control enters, choose one —
• You may tap or untap target creature.
• Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Vorinclex, Voice of Hunger

Trample
Whenever you tap a land for mana, add one mana of any type that land produced.
Whenever an opponent taps a land for mana, that land doesn't untap during its controller's next untap step.

Sol Ring

Negate

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Puppeteer

{U}, {T}: You may tap or untap target creature.

Seeker of Skybreak

Chakram Retriever

Partner with Chakram Slinger (When this creature enters, target player may put Chakram Slinger into their hand from their library, then shuffle.)
Whenever you cast a spell during your turn, untap target creature.