Hallowed Spiritkeeper

Vigilance
When Hallowed Spiritkeeper dies, create X 1/1 white Spirit creature tokens with flying, where X is the number of creature cards in your graveyard.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Time Wipe

Return a creature you control to its owner's hand, then destroy all creatures.

Sire of the Storm

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

Supreme Phantom

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

Nebelgast Herald

Flash (You may cast this spell any time you could cast an instant.)
Flying
Whenever Nebelgast Herald or another Spirit you control enters, tap target creature an opponent controls.

Counterspell

Moorland Haunt

{T}: Add {C}.
{W}{U}, {T}, Exile a creature card from your graveyard: Create a 1/1 white Spirit creature token with flying.

Sol Ring

Island

Swamp

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Custodi Soulbinders

Custodi Soulbinders enters with X +1/+1 counters on it, where X is the number of other creatures on the battlefield.
{2}{W}, Remove a +1/+1 counter from Custodi Soulbinders: Create a 1/1 white Spirit creature token with flying.

Arcane Signet

Forest

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Storm of Souls

Return all creature cards from your graveyard to the battlefield. Each of them is a 1/1 Spirit with flying in addition to its other types. Exile Storm of Souls.

Time Warp

Target player takes an extra turn after this one.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Atraxa, Praetors' Voice

Flying, vigilance, deathtouch, lifelink
At the beginning of your end step, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.

Oyobi, Who Split the Heavens

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

Plains

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Patrician Geist

Flying
Other Spirits you control get +1/+1.
Spells you cast from your graveyard cost {1} less to cast.

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.