Ugin, the Ineffable

Colorless spells you cast cost {2} less to cast.
+1: Exile the top card of your library face down and look at it. Create a 2/2 colorless Spirit creature token. When that token leaves the battlefield, put the exiled card into your hand.
−3: Destroy target permanent that's one or more colors.

Brago, King Eternal

Flying
Whenever Brago, King Eternal deals combat damage to a player, exile any number of target nonland permanents you control, then return those cards to the battlefield under their owner's control.

Celestial Kirin

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

Infernal Kirin

Flying
Whenever you cast a Spirit or Arcane spell, target player reveals their hand and discards all cards with that spell's mana value.

Ideas Unbound

Draw three cards. Discard three cards at the beginning of the next end step.

Dreamcatcher

Whenever you cast a Spirit or Arcane spell, you may sacrifice Dreamcatcher. If you do, draw a card.

Innocence Kami

{W}, {T}: Tap target creature.
Whenever you cast a Spirit or Arcane spell, untap Innocence Kami.

Sire of the Storm

Flying
Whenever you cast a Spirit or Arcane spell, you may draw a card.

Drogskol Reaver

Flying
Double strike (This creature deals both first-strike and regular combat damage.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Whenever you gain life, draw a card.

Iname, Death Aspect

When Iname, Death Aspect enters, you may search your library for any number of Spirit cards, put them into your graveyard, then shuffle.

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."

Clarion Spirit

Whenever you cast your second spell each turn, create a 1/1 white Spirit creature token with flying.

Rend Flesh

Field of Souls

Whenever a nontoken creature is put into your graveyard from the battlefield, create a 1/1 white Spirit creature token with flying.

Kyoki, Sanity's Eclipse

Whenever you cast a Spirit or Arcane spell, target opponent exiles a card from their hand.

Apothecary Geist

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

Ethereal Absolution

Creatures you control get +1/+1.
Creatures your opponents control get -1/-1.
{2}{W}{B}: Exile target card from an opponent's graveyard. If it was a creature card, you create a 1/1 white and black Spirit creature token with flying.

Spectral Shepherd

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

Kaya the Inexorable

+1: Put a ghostform counter on up to one target nontoken creature. It gains "When this creature dies or is put into exile, return it to its owner's hand and create a 1/1 white Spirit creature token with flying."
−3: Exile target nonland permanent.
−7: You get an emblem with "At the beginning of your upkeep, you may cast a legendary spell from your hand, from your graveyard, or from among cards you own in exile without paying its mana cost."

March of Souls

Destroy all creatures. They can't be regenerated. For each creature destroyed this way, its controller creates a 1/1 white Spirit creature token with flying.

Geist of Saint Traft

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Whenever Geist of Saint Traft attacks, create a 4/4 white Angel creature token with flying that's tapped and attacking. Exile that token at end of combat.

Soulless Revival

Return target creature card from your graveyard to your hand.
Splice onto Arcane {1}{B} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Divinity of Pride

Flying, lifelink
Divinity of Pride gets +4/+4 as long as you have 25 or more life.

Tallowisp

Whenever you cast a Spirit or Arcane spell, you may search your library for an Aura card with enchant creature, reveal it, put it into your hand, then shuffle.

Teller of Tales

Flying
Whenever you cast a Spirit or Arcane spell, you may tap or untap target creature.

Thief of Hope

Whenever you cast a Spirit or Arcane spell, target opponent loses 1 life and you gain 1 life.
Soulshift 2 (When this creature dies, you may return target Spirit card with mana value 2 or less from your graveyard to your hand.)

Ghastlord of Fugue

Ghastlord of Fugue can't be blocked.
Whenever Ghastlord of Fugue deals combat damage to a player, that player reveals their hand. You choose a card from it. That player exiles that card.

Skullmane Baku

Whenever you cast a Spirit or Arcane spell, you may put a ki counter on Skullmane Baku.
{1}, {T}, Remove X ki counters from Skullmane Baku: Target creature gets -X/-X until end of turn.

Battleground Geist

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

Ribbons of the Reikai

Eerie Procession

Search your library for an Arcane card, reveal that card, put it into your hand, then shuffle.

Gallows Warden

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

Drogskol Cavalry

Flying
Whenever another Spirit you control enters, you gain 2 life.
{3}{W}: Create a 1/1 white Spirit creature token with flying.

Drogskol Captain

Flying
Other Spirit creatures you control get +1/+1 and have hexproof. (They can't be the targets of spells or abilities your opponents control.)

Ertai, the Corrupted

{U}, {T}, Sacrifice a creature or enchantment: Counter target spell.

Supreme Phantom

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

Cloudhoof Kirin

Flying
Whenever you cast a Spirit or Arcane spell, you may have target player mill X cards, where X is that spell's mana value.