Verity Circle

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.
{4}{U}: Tap target creature without flying.

Leadership Vacuum

Target player returns each commander they control from the battlefield to the command zone.
Draw a card.

Letter of Acceptance

{T}: Add one mana of any color.
{2}, {T}, Sacrifice Letter of Acceptance: Draw a card.

Deserter's Quarters

You may choose not to untap Deserter's Quarters during your untap step.
{6}, {T}: Tap target creature. It doesn't untap during its controller's untap step for as long as Deserter's Quarters remains tapped.

Ice Floe

You may choose not to untap Ice Floe during your untap step.
{T}: Tap target creature without flying that's attacking you. It doesn't untap during its controller's untap step for as long as Ice Floe remains tapped.

Spinning Wheel

{T}: Add one mana of any color.
{5}, {T}: Tap target creature.

Grip of the Roil

Surge {1}{U} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)
Tap target creature. It doesn't untap during its controller's next untap step.
Draw a card.

Siren Song Lyre

Equipped creature has "{2}, {T}: Tap target creature."
Equip {2}

Icefall Regent

Flying
When Icefall Regent enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's untap step for as long as you control Icefall Regent.
Spells your opponents cast that target Icefall Regent cost {2} more to cast.

Rage of Winter

Tap target creature. It doesn't untap during its controller's next untap step. (Then exile this card. You may cast the creature later from exile.)

Queen of Ice

Whenever Queen of Ice deals combat damage to a creature, tap that creature. It doesn't untap during its controller's next untap step.

Queen of Ice // Rage of Winter

Rhystic Deluge

{U}: Tap target creature unless its controller pays {1}.

Blinding Drone

Devoid (This card has no color.)
{C}, {T}: Tap target creature. ({C} represents colorless mana.)

Choking Tethers

Tap up to four target creatures.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle Choking Tethers, you may tap target creature.

Quiet Contemplation

Whenever you cast a noncreature spell, you may pay {1}. If you do, tap target creature an opponent controls and it doesn't untap during its controller's next untap step.

Glacial Grasp

Tap target creature. Its controller mills two cards. That creature doesn't untap during its controller's next untap step. (They put the top two cards of their library into their graveyard.)
Draw a card.

Sleep of the Dead

Tap target creature. It doesn't untap during its controller's next untap step.
Escape—{2}{U}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Cephalid Retainer

{U}{U}: Tap target creature without flying.

Into the Roil

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Return target nonland permanent to its owner's hand. If this spell was kicked, draw a card.

Prophetic Prism

When Prophetic Prism enters the battlefield, draw a card.
{1}, {T}: Add one mana of any color.

Stitched Mangler

Stitched Mangler enters the battlefield tapped.
When Stitched Mangler enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Scour All Possibilities

Scry 2, then draw a card.
Flashback {4}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Tromokratis

Tromokratis has hexproof unless it's attacking or blocking.
Tromokratis can't be blocked unless all creatures defending player controls block it. (If any creature that player controls doesn't block this creature, it can't be blocked.)

Sand Squid

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
You may choose not to untap Sand Squid during your untap step.
{T}: Tap target creature. That creature doesn't untap during its controller's untap step for as long as Sand Squid remains tapped.

Drowner of Hope

Devoid (This card has no color.)
When Drowner of Hope enters the battlefield, create two 1/1 colorless Eldrazi Scion creature tokens. They have "Sacrifice this creature: Add {C}."
Sacrifice an Eldrazi Scion: Tap target creature.

Stonybrook Angler

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

Crown of Empires

{3}, {T}: Tap target creature. Gain control of that creature instead if you control artifacts named Scepter of Empires and Throne of Empires.

Niblis of the Breath

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

Press for Answers

Tap target creature. It doesn't untap during its controller's next untap step.
Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Rush of Ice

Tap target creature. It doesn't untap during its controller's next untap step.
Awaken 3—{4}{U} (If you cast this spell for {4}{U}, also put three +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)

Time of Ice

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Tap target creature an opponent controls. It doesn't untap during its controller's untap step for as long as you control Time of Ice.
III — Return all tapped creatures to their owners' hands.

Tyrant's Machine

Paradise Plume

As Paradise Plume enters the battlefield, choose a color.
Whenever a player casts a spell of the chosen color, you may gain 1 life.
{T}: Add one mana of the chosen color.

Hands of Binding

Tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.
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.)

Octopus Umbra

Enchant creature
Enchanted creature has base power and toughness 8/8 and has "Whenever this creature attacks, you may tap target creature with power 8 or less."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Retreat to Coralhelm

Landfall — Whenever a land enters the battlefield under your control, 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 of your library.)

Watertrap Weaver

When Watertrap Weaver enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Think Twice

Draw a card.
Flashback {2}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Blustersquall

Tap target creature you don't control.
Overload {3}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Ojutai's Breath

Tap target creature. It doesn't untap during its controller's next untap step.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Entrancing Lyre

You may choose not to untap Entrancing Lyre during your untap step.
{X}, {T}: Tap target creature with power X or less. It doesn't untap during its controller's untap step for as long as Entrancing Lyre remains tapped.

Trip Noose

Dungeon Geists

Flying
When Dungeon Geists enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's untap step for as long as you control Dungeon Geists.

Flood

Thassa's Ire

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

Frost Trickster

Flying
When Frost Trickster enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Tidal Bore

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
You may tap or untap target creature.

Puppeteer

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

Shoving Match

Until end of turn, all creatures gain "{T}: Tap target creature."

Teardrop Kami

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

Crippling Chill

Tap target creature. It doesn't untap during its controller's next untap step.
Draw a card.

Tolarian Kraken

Whenever you draw a card, you may pay {1}. When you do, you may tap or untap target creature.

Take into Custody

Tap target creature. It doesn't untap during its controller's next untap step.

Guardian of Tazeem

Flying
Landfall — Whenever a land enters the battlefield under your control, tap target creature an opponent controls. If that land is an Island, that creature doesn't untap during its controller's next untap step.