Sleep

Tap all creatures target player controls. Those creatures don't untap during that player's next untap step.

Court Street Denizen

Whenever another white creature you control enters, tap target creature an opponent controls.

Narcolepsy

Enchant creature
At the beginning of each upkeep, if enchanted creature is untapped, tap it.

Assassin Gauntlet

When Assassin Gauntlet enters, attach it to up to one target creature you control. Tap all creatures target opponent controls.
Equipped creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, draw a card, then discard a card."
Equip {2}

Plunge into Winter

Tap up to one target creature. Scry 1, then draw a card.

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.")

Solitary Sanctuary

When Solitary Sanctuary enters, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Whenever you tap an untapped creature an opponent controls, put a +1/+1 counter on target creature you control.

Hylda's Crown of Winter

{1}, {T}: Tap target creature. This ability costs {1} less to activate during your turn.
{3}, Sacrifice Hylda's Crown of Winter: Draw a card for each tapped creature your opponents control.

Cone of Cold

Roll a d20.
1—9 | Tap all creatures your opponents control.
10—19 | Tap all creatures your opponents control. Those creatures don't untap during their controllers' next untap steps.
20 | Tap all creatures your opponents control. Those creatures don't untap during their controllers' next untap steps. Until your next turn, creatures your opponents control enter tapped.

Icewrought Sentry

Vigilance
Whenever Icewrought Sentry attacks, you may pay {1}{U}. When you do, tap target creature an opponent controls.
Whenever you tap an untapped creature an opponent controls, Icewrought Sentry gets +2/+1 until end of turn.

Borrowing 100,000 Arrows

Draw a card for each tapped creature target opponent controls.

Minister of Impediments

({W/U} can be paid with either {W} or {U}.)
{T}: Tap target creature.

Opposition

Tap an untapped creature you control: Tap target artifact, creature, or land.

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Skycloud Expanse

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Hylda of the Icy Crown

Whenever you tap an untapped creature an opponent controls, you may pay {1}. When you do, choose one —
• Create a 4/4 white and blue Elemental creature token.
• Put a +1/+1 counter on each creature you control.
• Scry 2, then draw a card.

Dreamshackle Geist

Flying
At the beginning of combat on your turn, choose up to one —
• Tap target creature.
• Target creature doesn't untap during its controller's next untap step.

Timin, Youthful Geist

Partner with Rhoda, Geist Avenger (When this creature enters, target player may put Rhoda into their hand from their library, then shuffle.)
Flying
At the beginning of each combat, tap up to one target creature.

Curse of Chains

Enchant creature
At the beginning of each upkeep, tap enchanted creature.

Junk Winder

Affinity for tokens (This spell costs {1} less to cast for each token you control.)
Whenever a token you control enters, tap target nonland permanent an opponent controls. It doesn't untap during its controller's next untap step.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Gadwick, the Wizened

When Gadwick, the Wizened enters, draw X cards.
Whenever you cast a blue spell, tap target nonland permanent an opponent controls.

Gideon's Lawkeeper

Citadel Siege

As Citadel Siege enters, choose Khans or Dragons.
• Khans — At the beginning of combat on your turn, put two +1/+1 counters on target creature you control.
• Dragons — At the beginning of combat on each opponent's turn, tap target creature that player controls.

Talisman of Progress

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

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.

Glacial Fortress

Glacial Fortress enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Deserted Beach

Deserted Beach enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Sharae of Numbing Depths

When Sharae of Numbing Depths enters, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Whenever you tap one or more untapped creatures your opponents control, draw a card. This ability triggers only once each turn.

Topplegeist

Flying
When Topplegeist enters, tap target creature an opponent controls.
Delirium — At the beginning of each opponent's upkeep, if there are four or more card types among cards in your graveyard, tap target creature that player controls.