Have

Triplicate Spirits

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.)
Create three 1/1 white Spirit creature tokens with flying.

Spirits

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.

Not Forgotten

Put target card from a graveyard on your choice of the top or bottom of its owner's library. Create a 1/1 white Spirit creature token with flying.

Divine Verdict

Destroy target attacking or blocking creature.

Kami of Ancient Law

Sacrifice this creature: Destroy target enchantment.

Plains

Angel of Flight Alabaster

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

Gallows Warden

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

Pilgrim of the Ages

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

Eidolon of Rhetoric

Each player can't cast more than one spell each turn.

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 this creature enters, if you control no tapped lands, put two +1/+1 counters on it.

Selfless Spirit

Flying
Sacrifice this creature: Creatures you control gain indestructible until end of turn.

Hour of Reckoning

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.)
Destroy all nontoken creatures.

Apothecary Geist

Flying
When this creature enters, if you control another Spirit, you gain 3 life.

Devouring Light

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.)
Exile target attacking or blocking creature.

Thriving Heath

This land enters tapped. As it enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Doomed Traveler

When this creature dies, create a 1/1 white Spirit creature token with flying.

Mausoleum Guard

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