Eidolon of Philosophy

{6}{U}, Sacrifice this creature: Draw three cards.

Valor of the Worthy

Enchant creature
Enchanted creature gets +1/+1.
When enchanted creature leaves the battlefield, create a 1/1 white Spirit creature token with flying.

Empyrean Eagle

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

Ranar the Ever-Watchful

Flying, vigilance
The first card you foretell each turn costs {0} to foretell.
Whenever one or more cards are put into exile from your hand or a spell or ability you control exiles one or more permanents from the battlefield, create a 1/1 white Spirit creature token with flying.

Vega, the Watcher

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

Blessed Defiance

Target creature you control gets +2/+0 and gains lifelink until end of turn. When that creature dies this turn, create a 1/1 white Spirit creature token with flying.

Ghostly Castigator

Flying
When this creature enters, you may shuffle up to three target cards from your graveyard into your library.
If Ghostly Castigator would be put into a graveyard from anywhere, exile it instead.

Covetous Castaway

When this creature dies, mill three cards. (Put the top three cards of your library into your graveyard.)
Disturb {3}{U}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Covetous Castaway // Ghostly Castigator

Drogskol Shieldmate

Flash
When this creature enters, other creatures you control get +0/+1 until end of turn.

Mausoleum Guard

When this creature dies, create two 1/1 white Spirit creature tokens with flying.

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}

Luminous Phantom

Flying
Whenever another creature you control leaves the battlefield, you gain 1 life.
If Luminous Phantom would be put into a graveyard from anywhere, exile it instead.

Lunarch Veteran

Whenever another creature you control enters, you gain 1 life.
Disturb {1}{W} (You may cast this card from your graveyard transformed for its disturb cost.)

Lunarch Veteran // Luminous Phantom

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.)

Millicent, Restless Revenant

Affinity for Spirits (This spell costs {1} less to cast for each Spirit you control.)
Flying
Whenever Millicent or another nontoken Spirit you control dies or deals combat damage to a player, create a 1/1 white Spirit creature token with flying.

Soldier of the Grey Host

Flash
Flying
When this creature enters, target creature gets +2/+0 until end of turn.

Tower Geist

Flying
When this creature enters, look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.

Battleground Geist

Flying
Other Spirit creatures you control get +1/+0.

Accursed Duneyard

{T}: Add {C}.
{2}, {T}: Regenerate target Shade, Skeleton, Specter, Spirit, Vampire, Wraith, or Zombie. (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

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.

Guardian of Pilgrims

When this creature enters, target creature gets +1/+1 until end of turn.

Cosmos Charger

Flash
Flying
Foretelling cards from your hand costs {1} less and can be done on any player's turn.
Foretell {2}{U} (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.)

Anafenza, Unyielding Lineage

Flash
First strike
Whenever another nontoken creature you control dies, Anafenza endures 2. (Put two +1/+1 counters on it or create a 2/2 white Spirit creature token.)

Furious Forebear

Whenever a creature you control dies while this card is in your graveyard, you may pay {1}{W}. If you do, return this card from your graveyard to your hand.

Spell Queller

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