Ascendant Spirit

{S}{S}: Ascendant Spirit becomes a Spirit Warrior with base power and toughness 2/3.
{S}{S}{S}: If Ascendant Spirit is a Warrior, put a flying counter on it and it becomes a Spirit Warrior Angel with base power and toughness 4/4.
{S}{S}{S}{S}: If Ascendant Spirit is an Angel, put two +1/+1 counters on it and it gains "Whenever this creature deals combat damage to a player, draw a card."

Eiganjo, Seat of the Empire

{T}: Add {W}.
Channel — {2}{W}, Discard Eiganjo, Seat of the Empire: It deals 4 damage to target attacking or blocking creature. This ability costs {1} less to activate for each legendary creature you control.

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Mausoleum Wanderer

Flying
Whenever another Spirit enters the battlefield under your control, Mausoleum Wanderer gets +1/+1 until end of turn.
Sacrifice Mausoleum Wanderer: Counter target instant or sorcery spell unless its controller pays {X}, where X is Mausoleum Wanderer's power.

Combat Research

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
As long as enchanted creature is legendary, it gets +1/+1 and has ward {1}. (Whenever enchanted creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Lofty Denial

Counter target spell unless its controller pays {1}. If you control a creature with flying, counter that spell unless its controller pays {4} instead.

Aether Gust

Choose target spell or permanent that's red or green. Its owner puts it on the top or bottom of their library.

Geistlight Snare

This spell costs {1} less to cast if you control a Spirit. It also costs {1} less to cast if you control an enchantment.
Counter target spell unless its controller pays {3}.

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

Essence Scatter

Portable Hole

When Portable Hole enters the battlefield, exile target nonland permanent an opponent controls with mana value 2 or less until Portable Hole leaves the battlefield.

Pithing Needle

As Pithing Needle enters the battlefield, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Selfless Spirit

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

Lightshield Array

At the beginning of your end step, put a +1/+1 counter on each creature that attacked this turn.
Sacrifice Lightshield Array: Creatures you control gain hexproof and indestructible until end of turn.

Invasion of Gobakhan

(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 Invasion of Gobakhan enters the battlefield, look at target opponent's hand. You may exile a nonland card from it. For as long as that card remains exiled, its owner may play it. A spell cast this way costs {2} more to cast.

Invasion of Gobakhan // Lightshield Array

Settle the Wreckage

Exile all attacking creatures target player controls. That player may search their library for that many basic land cards, put those cards onto the battlefield tapped, then shuffle.

Wanderer's Intervention

Wanderer's Intervention deals 4 damage to target attacking or blocking creature.

Faceless Haven

{T}: Add {C}.
{S}{S}{S}: Faceless Haven becomes a 4/3 creature with vigilance and all creature types until end of turn. It's still a land. ({S} can be paid with one mana from a snow source.)

Surge of Salvation

You and permanents you control gain hexproof until end of turn. Prevent all damage that black and/or red sources would deal to creatures you control this turn.

Seachrome Coast

Seachrome Coast enters the battlefield tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Shacklegeist

Flying
Shacklegeist can block only creatures with flying.
Tap two untapped Spirits you control: Tap target creature you don't control.

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice Curious Obsession.

Snow-Covered Island

Brinebound Gift

Enchant creature
Whenever Brinebound Gift enters the battlefield or enchanted creature becomes the target of an Aura spell, create a 1/1 white Spirit creature token with flying.
If Brinebound Gift would be put into a graveyard from anywhere, exile it instead.

Brine Comber

Whenever Brine Comber enters the battlefield or becomes the target of an Aura spell, create a 1/1 white Spirit creature token with flying.
Disturb {W}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Brine Comber // Brinebound Gift

Destroy Evil

Choose one —
• Destroy target creature with toughness 4 or greater.
• Destroy target enchantment.

Snow-Covered Plains

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Supreme Phantom

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

Ossification

Enchant basic land you control
When Ossification enters the battlefield, exile target creature or planeswalker an opponent controls until Ossification leaves the battlefield.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Spell Queller

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

Rattlechains

Flash
Flying
When Rattlechains enters the battlefield, target Spirit gains hexproof until end of turn.
You may cast Spirit spells as though they had flash.