Dovin's Veto

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

Plains

Glacial Fortress

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

Sorcerous Spyglass

As Sorcerous Spyglass enters, look at an opponent's hand, then choose any card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice Curious Obsession.

Rattlechains

Flash
Flying
When Rattlechains enters, target Spirit gains hexproof until end of turn.
You may cast Spirit spells as though they had flash.

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

Island

Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Favorable Winds

Creatures you control with flying get +1/+1.

Petty Theft

Return target nonland permanent an opponent controls to its owner's hand.

Brazen Borrower

Flash
Flying
Brazen Borrower can block only creatures with flying.

Brazen Borrower // Petty Theft

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Remorseful Cleric

Flying
Sacrifice Remorseful Cleric: Exile target player's graveyard.

Mausoleum Wanderer

Flying
Whenever another Spirit you control enters, Mausoleum Wanderer gets +1/+1 until end of turn.
Sacrifice Mausoleum Wanderer: Counter target instant or sorcery spell unless its controller pays {X}, where X is Mausoleum Wanderer's power.

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.

Supreme Phantom

Flying
Other Spirits you control get +1/+1.

Spell Queller

Flash
Flying
When Spell Queller enters, exile target spell with mana value 4 or less.
When Spell Queller leaves the battlefield, the exiled card's owner may cast that card without paying its mana cost.

Selfless Spirit

Flying
Sacrifice Selfless Spirit: Creatures you control gain indestructible until end of turn.

Detention Sphere

When Detention Sphere enters, you may exile target nonland permanent not named Detention Sphere and all other permanents with the same name as that permanent.
When Detention Sphere leaves the battlefield, return the exiled cards to the battlefield under their owner's control.

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}.

Smuggler's Copter

Flying
Whenever Smuggler's Copter attacks or blocks, you may draw a card. If you do, discard a card.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Sky Tether

Enchant creature
Enchanted creature has defender and loses flying.

Teferi, Time Raveler

Each opponent can cast spells only any time they could cast a sorcery.
+1: Until your next turn, you may cast sorcery spells as though they had flash.
−3: Return up to one target artifact, creature, or enchantment to its owner's hand. Draw a card.

Negate

Mystical Dispute

This spell costs {2} less to cast if it targets a blue spell.
Counter target spell unless its controller pays {3}.