Mercurial Spelldancer

Mercurial Spelldancer can't be blocked.
Whenever you cast a noncreature spell, put an oil counter on Mercurial Spelldancer.
Whenever Mercurial Spelldancer deals combat damage to a player, you may remove two oil counters from it. If you do, when you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Teferi's Veil

Whenever a creature you control attacks, it phases out at end of combat. (While it's phased out, it's treated as though it doesn't exist. It phases in before you untap during your next untap step.)

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Forbid

Buyback—Discard two cards. (You may discard two cards in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Counter target spell.

Inkmoth Nexus

{T}: Add {C}.
{1}: Inkmoth Nexus becomes a 1/1 Phyrexian Blinkmoth artifact creature with flying and infect until end of turn. It's still a land. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle Elixir of Immortality and your graveyard into their owner's library.

Thalakos Sentry

Shadow (This creature can block or be blocked by only creatures with shadow.)

Cloud of Faeries

Flying
When Cloud of Faeries enters, untap up to two lands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Island

Scryb Sprites

Edric, Spymaster of Trest

Whenever a creature deals combat damage to one of your opponents, its controller may draw a card.

Slip Through Space

Devoid (This card has no color.)
Target creature can't be blocked this turn.
Draw a card.

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Blighted Agent can't be blocked.

Escape Artist

Escape Artist can't be blocked.
{U}, Discard a card: Return Escape Artist to its owner's hand.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Druids' Repository

Whenever a creature you control attacks, put a charge counter on Druids' Repository.
Remove a charge counter from Druids' Repository: Add one mana of any color.

Hypnotic Siren

Bestow {5}{U}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying
You control enchanted creature.
Enchanted creature gets +1/+1 and has flying.

Beastmaster Ascension

Whenever a creature you control attacks, you may put a quest counter on Beastmaster Ascension.
As long as Beastmaster Ascension has seven or more quest counters on it, creatures you control get +5/+5.

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Wingcrafter

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Wingcrafter is paired with another creature, both creatures have flying.

Hope of Ghirapur

Flying
Sacrifice Hope of Ghirapur: Until your next turn, target player who was dealt combat damage by Hope of Ghirapur this turn can't cast noncreature spells.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Seafaring Werewolf

Seafaring Werewolf can't be blocked.
Whenever Seafaring Werewolf deals combat damage to a player, draw a card.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Suspicious Stowaway

Suspicious Stowaway can't be blocked.
Whenever Suspicious Stowaway deals combat damage to a player, draw a card, then discard a card.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Suspicious Stowaway // Seafaring Werewolf

Mystic Snake

Flash
When Mystic Snake enters, counter target spell.

Notorious Throng

Prowl {5}{U} (You may cast this for its prowl cost if you dealt combat damage to a player this turn with a Rogue.)
Create X 1/1 black Faerie Rogue creature tokens with flying, where X is the damage dealt to your opponents this turn. If this spell's prowl cost was paid, take an extra turn after this one.

Dryad Sophisticate

Nonbasic landwalk (This creature can't be blocked as long as defending player controls a nonbasic land.)

Shriekgeist

Flying
Whenever Shriekgeist deals combat damage to a player, that player mills two cards.

Uktabi Drake

Flying, haste
Echo {1}{G}{G} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)

Cloud Pirates

Flying
Cloud Pirates can block only creatures with flying.

Shoreline Looter

Shoreline Looter can't be blocked.
Threshold — Whenever Shoreline Looter deals combat damage to a player, draw a card. Then discard a card unless seven or more cards are in your graveyard.

Jace's Phantasm

Flying
Jace's Phantasm gets +4/+4 as long as an opponent has ten or more cards in their graveyard.

Flying Men

Cold-Eyed Selkie

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever Cold-Eyed Selkie deals combat damage to a player, you may draw that many cards.

Warkite Marauder

Flying
Whenever Warkite Marauder attacks, target creature defending player controls loses all abilities and has base power and toughness 0/1 until end of turn.

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

Moment's Peace

Prevent all combat damage that would be dealt this turn.
Flashback {2}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

One with Nature

Enchant creature
Whenever enchanted creature deals combat damage to a player, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Preposterous Proportions

Creatures you control get +10/+10 and gain vigilance until end of turn.

Slither Blade

Forest

Spiketail Hatchling

Flying (This creature can't be blocked except by creatures with flying or reach.)
Sacrifice Spiketail Hatchling: Counter target spell unless its controller pays {1}.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Triton Shorestalker

Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.

Looter il-Kor

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Looter il-Kor deals damage to an opponent, draw a card, then discard a card.

Spore Frog

Sacrifice Spore Frog: Prevent all combat damage that would be dealt this turn.

Beast Within

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

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.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Nullmage Shepherd

Tap four untapped creatures you control: Destroy target artifact or enchantment.

Chasm Skulker

Whenever you draw a card, put a +1/+1 counter on Chasm Skulker.
When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)

Shadow Rift

Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)
Draw a card.

Essence Warden

Whenever another creature enters, you gain 1 life.

Spire Tracer

Spire Tracer can't be blocked except by creatures with flying or reach.

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Mist-Cloaked Herald

Jhessian Infiltrator

Silhana Ledgewalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Silhana Ledgewalker can't be blocked except by creatures with flying.

Command Tower

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

Burgeoning

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

True-Name Nemesis

As True-Name Nemesis enters, choose a player.
True-Name Nemesis has protection from the chosen player.

Kira, Great Glass-Spinner

Flying
Creatures you control have "Whenever this creature becomes the target of a spell or ability for the first time each turn, counter that spell or ability."

Harvest Season

Search your library for up to X basic land cards, where X is the number of tapped creatures you control, put those cards onto the battlefield tapped, then shuffle.

Invisible Stalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Invisible Stalker can't be blocked.

Gudul Lurker

Gudul Lurker can't be blocked.
Megamorph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Aluren

Any player may cast creature spells with mana value 3 or less without paying their mana costs and as though they had flash.

Faerie Seer

Trygon Predator

Flying
Whenever Trygon Predator deals combat damage to a player, you may destroy target artifact or enchantment that player controls.

Thalakos Seer

Shadow (This creature can block or be blocked by only creatures with shadow.)
When Thalakos Seer leaves the battlefield, draw a card.

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.)

Flitterstep Eidolon

Bestow {5}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flitterstep Eidolon can't be blocked.
Enchanted creature gets +1/+1 and can't be blocked.

Sage Owl

Flying
When Sage Owl enters, look at the top four cards of your library, then put them back in any order.