Hikari, Twilight Guardian

Flying
Whenever you cast a Spirit or Arcane spell, you may exile Hikari, Twilight Guardian. If you do, return it to the battlefield under its owner's control at the beginning of the next end step.

Oyobi, Who Split the Heavens

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

Yosei, the Morning Star

Flying
When Yosei, the Morning Star dies, target player skips their next untap step. Tap up to five target permanents that player controls.

Anafenza, Kin-Tree Spirit

Whenever another nontoken creature you control enters, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Nikko-Onna

When Nikko-Onna enters, destroy target enchantment.
Whenever you cast a Spirit or Arcane spell, you may return Nikko-Onna to its owner's hand.

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

Waxmane Baku

Whenever you cast a Spirit or Arcane spell, you may put a ki counter on Waxmane Baku.
{1}, Remove X ki counters from Waxmane Baku: Tap X target creatures.

Hollowhenge Spirit

Flash (You may cast this spell any time you could cast an instant.)
Flying
When Hollowhenge Spirit enters, remove target attacking or blocking creature from combat.

Horizon Seed

Whenever you cast a Spirit or Arcane spell, regenerate target creature.

Gift of Immortality

Enchant creature
When enchanted creature dies, return that card to the battlefield under its owner's control. Return Gift of Immortality to the battlefield attached to that creature at the beginning of the next end step.

Angel of Flight Alabaster

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

Kami of False Hope

Sacrifice Kami of False Hope: Prevent all combat damage that would be dealt this turn.

Ethereal Haze

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

Ephemeral Shields

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.)
Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Guardian of Faith

Flash
Vigilance
When Guardian of Faith 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.)

Bastion Protector

Commander creatures you control get +2/+2 and have indestructible.

Otherworldly Journey

Exile target creature. At the beginning of the next end step, return that card to the battlefield under its owner's control with a +1/+1 counter on it.

Endless Atlas

{2}, {T}: Draw a card. Activate only if you control three or more lands with the same name.

Plains

Pilgrim of the Ages

When Pilgrim of the Ages enters, you may search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
{6}: Return Pilgrim of the Ages from your graveyard to your hand.

Wand of the Worldsoul

Wand of the Worldsoul enters tapped.
{T}: Add {W}.
{T}: The next spell you cast this turn has convoke.

Kami of Ancient Law

Sacrifice Kami of Ancient Law: Destroy target enchantment.

Boon of Safety

Put a shield counter on target creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Scry 1.

Terashi's Grasp

Destroy target artifact or enchantment. You gain life equal to its mana value.

Martyr's Soul

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.)
When Martyr's Soul enters, if you control no tapped lands, put two +1/+1 counters on it.

Oketra's Monument

White creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, create a 1/1 white Warrior creature token with vigilance.

Folk Hero

Commander creatures you own have "Whenever you cast a spell that shares a creature type with this creature, draw a card. This ability triggers only once each turn."

Selfless Spirit

Flying
Sacrifice Selfless Spirit: Creatures you control gain indestructible until end of turn.

Spirit of the Labyrinth

Each player can't draw more than one card each turn.

Sejiri Glacier

Sejiri Glacier enters tapped.
{T}: Add {W}.

Sejiri Shelter

Target creature you control gains protection from the color of your choice until end of turn.

Sejiri Shelter // Sejiri Glacier

Eternal Dragon

Flying
{3}{W}{W}: Return Eternal Dragon from your graveyard to your hand. Activate only during your upkeep.
Plainscycling {2} ({2}, Discard this card: Search your library for a Plains card, reveal it, put it into your hand, then shuffle.)

Dust Animus

Flying
If you control five or more untapped lands, Dust Animus enters with two +1/+1 counters and a lifelink counter on it.
Plot {1}{W} (You may pay {1}{W} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Omarthis, Ghostfire Initiate

Omarthis, Ghostfire Initiate enters with X +1/+1 counters on it.
Whenever you put one or more +1/+1 counters on another colorless creature, you may put a +1/+1 counter on Omarthis.
When Omarthis dies, manifest a number of cards from the top of your library equal to the number of counters on it.

Keening Apparition

Sacrifice Keening Apparition: Destroy target enchantment.

Katilda's Rising Dawn

Enchant creature
Enchanted creature has flying, lifelink, and protection from Vampires, and it gets +X/+X, where X is the number of permanents you control that are Spirits and/or enchantments.
If Katilda's Rising Dawn would be put into a graveyard from anywhere, exile it instead.

Katilda, Dawnhart Martyr

Flying, lifelink, protection from Vampires
Katilda, Dawnhart Martyr's power and toughness are each equal to the number of permanents you control that are Spirits and/or enchantments.
Disturb {3}{W}{W} (You may cast this card from your graveyard transformed for its disturb cost.)

Katilda, Dawnhart Martyr // Katilda's Rising Dawn

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Heraldic Banner

As Heraldic Banner enters, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Moonshaker Cavalry

Flying
When Moonshaker Cavalry enters, creatures you control gain flying and get +X/+X until end of turn, where X is the number of creatures you control.

Celestial Kirin

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

Skyclave Apparition

When Skyclave Apparition enters, exile up to one target nonland, nontoken permanent you don't control with mana value 4 or less.
When Skyclave Apparition leaves the battlefield, the exiled card's owner creates an X/X blue Illusion creature token, where X is the mana value of the exiled card.

Bygone Bishop

Flying
Whenever you cast a creature spell with mana value 3 or less, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Windborn Muse

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

Ugin's Conjurant

Ugin's Conjurant enters with X +1/+1 counters on it.
If damage would be dealt to Ugin's Conjurant while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from Ugin's Conjurant.

Rescuer Chwinga

Flash
Natural Shelter — When Rescuer Chwinga enters, you may return another permanent you control to its owner's hand.

Charge Across the Araba

Sweep — Return any number of Plains you control to their owner's hand. Creatures you control get +1/+1 until end of turn for each Plains returned this way.