Celestial Crusader

Flash
Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Flying
Other white creatures get +1/+1.

Urborg Scavengers

Whenever this creature enters or attacks, exile target card from a graveyard. Put a +1/+1 counter on this creature.
This creature has flying as long as a card exiled with it has flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Andúril, Flame of the West

Equipped creature gets +3/+1.
Whenever equipped creature attacks, create two tapped 1/1 white Spirit creature tokens with flying. If that creature is legendary, instead create two of those tokens that are tapped and attacking.
Equip {2}

Grey Host Reinforcements

Flying, ward {3}
When this creature enters, exile target player's graveyard. Put a number of +1/+1 counters on this creature equal to the number of creature cards exiled this way.

Swords to Plowshares

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

Priest of the Blessed Graf

At the beginning of your end step, create X 1/1 white Spirit creature tokens with flying, where X is the number of opponents who control more lands than you.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Angel of Flight Alabaster

Flying
At the beginning of your upkeep, return target Spirit card from your graveyard to your hand.

Lingering Souls

Create two 1/1 white Spirit creature tokens with flying.
Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Selfless Spirit

Flying
Sacrifice this creature: Creatures you control gain indestructible until end of turn.

Kaya, Geist Hunter

+1: Creatures you control gain deathtouch until end of turn. Put a +1/+1 counter on up to one target creature token you control.
−2: Until end of turn, if one or more tokens would be created under your control, twice that many of those tokens are created instead.
−6: Exile all cards from all graveyards, then create a 1/1 white Spirit creature token with flying for each card exiled this way.

Cauldron Haze

Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it 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.)

Drogskol Reinforcements

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Other Spirits you control have melee.
Prevent all noncombat damage that would be dealt to Spirits you control.

King of the Oathbreakers

Flying
Whenever King of the Oathbreakers or another Spirit you control becomes the target of a spell, it phases out. (Treat it and anything attached to it as though they don't exist until your next turn.)
Whenever King of the Oathbreakers or another Spirit you control phases in, create a tapped 1/1 white Spirit creature token with flying.

The Broken Sky

Creature tokens you control get +1/+0 and have lifelink.
At the beginning of your end step, create a 1/1 white and black Spirit creature token with flying.

Invasion of Tolvada

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, return target nonbattle permanent card from your graveyard to the battlefield.

Invasion of Tolvada // The Broken Sky

Clever Concealment

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Any number of target nonland permanents you control phase out. (Treat them and anything attached to them as though they don't exist until your next turn.)

Windborn Muse

Flying
Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Touch of Darkness

One or more target creatures become black until end of turn.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

He Who Hungers

Flying
{1}, Sacrifice a Spirit: Target opponent reveals their hand. You choose a card from it. That player discards that card. Activate only as a sorcery.
Soulshift 4 (When this creature dies, you may return target Spirit card with mana value 4 or less from your graveyard to your hand.)

Haunted Library

Whenever a creature an opponent controls dies, you may pay {1}. If you do, create a 1/1 white Spirit creature token with flying.

Horobi, Death's Wail

Flying
Whenever a creature becomes the target of a spell or ability, destroy that creature.

Guardian of Faith

Flash
Vigilance
When this creature enters, any number of other target creatures you control phase out. (Treat them and anything attached to them as though they don't exist until their controller's next turn.)

Shadow Summoning

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

Architect of Restoration

Vigilance
Whenever this creature attacks or blocks, create a 1/1 colorless Spirit creature token.

The Restoration of Eiganjo

(As this Saga enters and after your draw step, add a lore counter.)
I — Search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
II — You may discard a card. When you do, return target permanent card with mana value 2 or less from your graveyard to the battlefield tapped.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Restoration of Eiganjo // Architect of Restoration

Thalisse, Reverent Medium

At the beginning of each end step, create X 1/1 white Spirit creature tokens with flying, where X is the number of tokens you created this turn.

Heaven's Gate

One or more target creatures become white until end of turn.

Ghostly Prison

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Myojin of Blooming Dawn

Myojin of Blooming Dawn enters with an indestructible counter on it if you cast it from your hand.
Remove an indestructible counter from Myojin of Blooming Dawn: Create a 1/1 colorless Spirit creature token for each permanent you control.

Twilight Drover

Whenever a creature token leaves the battlefield, put a +1/+1 counter on this creature.
{2}{W}, Remove a +1/+1 counter from this creature: Create two 1/1 white Spirit creature tokens with flying.

Oyobi, Who Split the Heavens

Flying
Whenever you cast a Spirit or Arcane spell, create a 3/3 white Spirit creature token with flying.

Ethereal Haze

Prevent all damage that would be dealt by creatures this turn.

Choice of Damnations

Target opponent chooses a number. You may have that player lose that much life. If you don't, that player sacrifices all but that many permanents of their choice.