Gigadrowse

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Tap target permanent.

Goldmeadow Harrier

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.)

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Ornithopter of Paradise

Exotic Orchard

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

Bond of Discipline

Tap all creatures your opponents control. Creatures you control gain lifelink until end of turn.

Ojutai Exemplars

Whenever you cast a noncreature spell, choose one —
• Tap target creature.
• Ojutai Exemplars gains first strike and lifelink until end of turn.
• Exile Ojutai Exemplars, then return it to the battlefield tapped under its owner's control.

Azorius Signet

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Tempest Caller

When Tempest Caller enters, tap all creatures target opponent controls.

Deluge

Opposition

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

Silver Myr

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Githzerai Monk

Flash
Flying
Psychic Defense — When Githzerai Monk enters, tap all creatures you don't control.

Arcane Signet

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

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.

Gadwick, the Wizened

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

Talisman of Progress

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

Knight of the White Orchid

First strike
When Knight of the White Orchid enters, if an opponent controls more lands than you, you may search your library for a Plains card, put it onto the battlefield, then shuffle.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Succumb to the Cold

Tap one or two target creatures an opponent controls. Put a stun counter on each of them. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Gideon's Lawkeeper

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Fellwar Stone

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.

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.

Detection Tower

{T}: Add {C}.
{1}, {T}: Until end of turn, your opponents and creatures your opponents control with hexproof can be the targets of spells and abilities you control as though they didn't have hexproof.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Flood

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

Sol Ring

Snow-Covered Island

Frost Titan

Whenever Frost Titan becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.
Whenever Frost Titan enters or attacks, tap target permanent. It doesn't untap during its controller's next untap step.

Subjugator Angel

Flying
When Subjugator Angel enters, tap all creatures your opponents control.

Icy Blast

Tap X target creatures.
Ferocious — If you control a creature with power 4 or greater, those creatures don't untap during their controllers' next untap steps.

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.

Lossarnach Captain

First strike
Whenever Lossarnach Captain or another Human you control enters, tap target creature an opponent controls.
At the beginning of your upkeep, create a 1/1 white Human Soldier creature token.

Cryptic Command

Choose two —
• Counter target spell.
• Return target permanent to its owner's hand.
• Tap all creatures your opponents control.
• Draw a card.

Borrowing 100,000 Arrows

Draw a card for each tapped creature target opponent controls.

Angel's Trumpet

All creatures have vigilance.
At the beginning of each player's end step, tap all untapped creatures that player controls that didn't attack this turn. Angel's Trumpet deals damage to the player equal to the number of creatures tapped this way.

Turnabout

Choose artifact, creature, or land. Tap all untapped permanents of the chosen type target player controls, or untap all tapped permanents of that type that player controls.

Downpour

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.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Negate

Ensnare

You may return two Islands you control to their owner's hand rather than pay this spell's mana cost.
Tap all creatures.

Sunblast Angel

Flying
When Sunblast Angel enters, destroy all tapped creatures.

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.")

Gold Myr

Gideon's Avenger

Whenever a creature an opponent controls becomes tapped, put a +1/+1 counter on Gideon's Avenger.

Mind Stone

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

Port Town

As Port Town enters, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters tapped.
{T}: Add {W} or {U}.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

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.

Loyal Warhound

Vigilance
When Loyal Warhound enters, if an opponent controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Snow-Covered Plains

Theft of Dreams

Command Tower

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Niblis of Frost

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast an instant or sorcery spell, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Sleep

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

Glacial Floodplain

({T}: Add {W} or {U}.)
Glacial Floodplain enters tapped.

Aboshan, Cephalid Emperor

Tap an untapped Octopus you control: Tap target permanent.
{U}{U}{U}: Tap all creatures without flying.

Drumbellower

Flying
Untap all creatures you control during each other player's untap step.

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.

Faramir, Prince of Ithilien

At the beginning of your end step, choose an opponent. At the beginning of that player's next end step, you draw a card if they didn't attack you that turn. Otherwise, create three 1/1 white Human Soldier creature tokens.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.