Marketwatch Phantom

Whenever another creature you control with power 2 or less enters, Marketwatch Phantom gains flying until end of turn.

Muster the Departed

When Muster the Departed enters, create a 1/1 white Spirit creature token with flying.
Morbid — At the beginning of your end step, if a creature died this turn, populate. (Create a token that's a copy of a creature token you control.)

Moorland Drifter

Delirium — Moorland Drifter has flying as long as there are four or more card types among cards in your graveyard.

Unimpeded Trespasser

Uninvited Geist

Skulk (This creature can't be blocked by creatures with greater power.)
When Uninvited Geist deals combat damage to a player, transform it.

Uninvited Geist // Unimpeded Trespasser

Oath of the Grey Host

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — You and target opponent each create a Food token.
II — Each opponent loses 3 life. Create a Treasure token.
III — Create three tapped 1/1 white Spirit creature tokens with flying.

Aron, Benalia's Ruin

Menace (This creature can't be blocked except by two or more creatures.)
{W}{B}, {T}, Sacrifice another creature: Put a +1/+1 counter on each creature you control.

Wanderlight Spirit

Flying
Wanderlight Spirit can block only creatures with flying.

Deduce

Draw a card. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Phantom Interference

Spree (Choose one or more additional costs.)
+ {3} — Create a 2/2 white Spirit creature token with flying.
+ {1} — Counter target spell unless its controller pays {2}.

Aid the Fallen

Choose one or both —
• Return target creature card from your graveyard to your hand.
• Return target planeswalker card from your graveyard to your hand.

Fog on the Barrow-Downs

Enchant creature
Enchanted creature is a Spirit and can't attack or block. (It loses all other creature types.)

Skycloud Expanse

Niblis of Dusk

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Momentary Blink

Exile target creature you control, then return it to the battlefield under its owner's control.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Cleave Shadows

Creatures your opponents control get -1/-1 until end of turn. (Then exile this card. You may cast the creature later from exile.)

Shrouded Shepherd

When Shrouded Shepherd enters, target creature you control gets +2/+2 until end of turn.

Shrouded Shepherd // Cleave Shadows

Teysa Karlov

If a creature dying causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Creature tokens you control have vigilance and lifelink.

Suffocating Fumes

Creatures your opponents control get -1/-1 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

On the Job

Creatures you control get +2/+1 until end of turn. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Rise of Extus

Exile target creature. Exile up to one target instant or sorcery card from a graveyard.
Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Warhorn Blast

Creatures you control get +2/+1 until end of turn.
Foretell {2}{W} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Screaming Phantom

Flying
Whenever Screaming Phantom attacks, mill a card. (Put the top card of your library into your graveyard.)

Obscura Ascendancy

Whenever you cast a spell, if its mana value is equal to 1 plus the number of soul counters on Obscura Ascendancy, put a soul counter on Obscura Ascendancy, then create a 2/2 white Spirit creature token with flying.
As long as there are five or more soul counters on Obscura Ascendancy, Spirits you control get +3/+3.

Island

Beckoning Will-o'-Wisp

Flying
Lure the Unwary — At the beginning of combat on your turn, choose an opponent.
Creatures attacking the last chosen player get +1/+0.

Shadow Summoning

Create two tapped 1/1 white Spirit creature tokens with flying.

Tattered Haunter

Flying
Tattered Haunter can block only creatures with flying.

Apothecary Geist

Flying
When Apothecary Geist enters, if you control another Spirit, you gain 3 life.

Farbog Revenant

Skulk (This creature can't be blocked by creatures with greater power.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Soldier of the Grey Host

Flash
Flying
When Soldier of the Grey Host enters, target creature gets +2/+0 until end of turn.

Aminatou, the Fateshifter

+1: Draw a card, then put a card from your hand on top of your library.
−1: Exile another target permanent you own, then return it to the battlefield under your control.
−6: Choose left or right. Each player gains control of all nonland permanents other than Aminatou, the Fateshifter controlled by the next player in the chosen direction.
Aminatou, the Fateshifter can be your commander.

Chapel Geist

Defend the Campus

Choose one —
• Creatures you control get +1/+1 until end of turn.
• Destroy target creature with power 4 or greater.

Vega, the Watcher

Flying
Whenever you cast a spell from anywhere other than your hand, draw a card.

Echo of Dusk

Descend 4 — As long as there are four or more permanent cards in your graveyard, Echo of Dusk gets +1/+1 and has lifelink.

Abuelo, Ancestral Echo

Flying, ward {2}
{1}{W}{U}: Exile another target creature or artifact you control. Return it to the battlefield under its owner's control at the beginning of the next end step.

Proft's Eidetic Memory

When Proft's Eidetic Memory enters, draw a card.
You have no maximum hand size.
At the beginning of combat on your turn, if you've drawn more than one card this turn, put X +1/+1 counters on target creature you control, where X is the number of cards you've drawn this turn minus one.

Treacherous Greed

As an additional cost to cast this spell, sacrifice a creature that dealt damage this turn.
Draw three cards. Each opponent loses 3 life and you gain 3 life.

Quicksand Whirlpool

This spell costs {3} less to cast if it targets a tapped creature.
Exile target creature.

Council of Echoes

Flying
Descend 4 — When Council of Echoes enters, if there are four or more permanent cards in your graveyard, return up to one target nonland permanent other than Council of Echoes to its owner's hand.

Castigate

Target opponent reveals their hand. You choose a nonland card from it and exile that card.

Obscura Storefront

When Obscura Storefront enters, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Accursed Spirit

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Spectral Shepherd

Flying
{1}{U}: Return target Spirit you control to its owner's hand.

Plains

Dungeon Geists

Flying
When Dungeon Geists enters, 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.

Kami of Restless Shadows

When Kami of Restless Shadows enters, choose one —
• Return up to one target Ninja or Rogue creature card from your graveyard to your hand.
• Put target creature card from your graveyard on top of your library.

Didact Echo

When Didact Echo enters, draw a card.
Descend 4 — Didact Echo has flying as long as there are four or more permanent cards in your graveyard.

Celestial Kirin

Flying
Whenever you cast a Spirit or Arcane spell, destroy all permanents with that spell's mana value.

Unauthorized Exit

Return target nonland permanent to its owner's hand. Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Humiliate

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card. Put a +1/+1 counter on a creature you control.

Soul Search

Target opponent reveals their hand. You choose a nonland card from it. Exile that card. If the card's mana value is 1 or less, create a 1/1 white and black Spirit creature token with flying.

Elas il-Kor, Sadistic Pilgrim

Deathtouch
Whenever another creature you control enters, you gain 1 life.
Whenever another creature you control dies, each opponent loses 1 life.

Silent Observer

Gravelighter

Flying
When Gravelighter enters, draw a card if a creature died this turn. Otherwise, each player sacrifices a creature of their choice.

Reasonable Doubt

Counter target spell unless its controller pays {2}.
Suspect up to one target creature. (A suspected creature has menace and can't block.)

Skulking Ghost

Flying
When Skulking Ghost becomes the target of a spell or ability, sacrifice it.

Eerie Soultender

When Eerie Soultender enters, mill three cards. (Put the top three cards of your library into your graveyard.)
{4}{B}, Exile Eerie Soultender from your graveyard: Return another target creature card from your graveyard to your hand.

Teferi's Talent

Enchant planeswalker
Enchanted planeswalker has "[−12]: You get an emblem with 'You may activate loyalty abilities of planeswalkers you control on any player's turn any time you could cast an instant.'"
Whenever you draw a card, put a loyalty counter on enchanted planeswalker.

Make Your Move

Destroy target artifact, enchantment, or creature with power 4 or greater.

Abuelo's Awakening

Return target artifact or non-Aura enchantment card from your graveyard to the battlefield with X additional +1/+1 counters on it. It's a 1/1 Spirit creature with flying in addition to its other types.

Twinblade Invocation

Enchant creature
Enchanted creature has double strike.
If Twinblade Invocation would be put into a graveyard from anywhere, exile it instead.

Twinblade Geist

Double strike
Disturb {2}{W} (You may cast this card from your graveyard transformed for its disturb cost.)

Twinblade Geist // Twinblade Invocation

Fogwalker

Skulk (This creature can't be blocked by creatures with greater power.)
When Fogwalker enters, target creature an opponent controls doesn't untap during its controller's next untap step.

World-Weary

Enchant creature
Enchanted creature gets -4/-4.
Basic landcycling {1}{B} ({1}{B}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Expel

Restless Apparition

{W/B}{W/B}{W/B}: Restless Apparition gets +3/+3 until end of turn.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Swamp

Doomed Traveler

When Doomed Traveler dies, create a 1/1 white Spirit creature token with flying.

Lanterns' Lift

Enchant creature
Enchanted creature gets +1/+1 and has flying.
If Lanterns' Lift would be put into a graveyard from anywhere, exile it instead.

Lantern Bearer

Flying
Disturb {2}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Lantern Bearer // Lanterns' Lift

Cipherbound Spirit

Flying
Cipherbound Spirit can block only creatures with flying.
{3}{U}: Draw two cards, then discard a card.

Soulcipher Board

Soulcipher Board enters with three omen counters on it.
{1}{U}, {T}: Look at the top two cards of your library. Put one of them into your graveyard.
Whenever a creature card is put into your graveyard from anywhere, remove an omen counter from Soulcipher Board. Then if it has no omen counters on it, transform it.

Soulcipher Board // Cipherbound Spirit

Exhilarating Elocution

Put two +1/+1 counters on target creature you control. Other creatures you control get +1/+1 until end of turn.