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.

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.

Port Town

As Port Town enters, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters tapped.
{T}: Add {W} or {U}.

Spell Queller

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

Ao, the Dawn Sky

Flying, vigilance
When Ao, the Dawn Sky dies, choose one —
• Look at the top seven cards of your library. Put any number of nonland permanent cards with total mana value 4 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.
• Put two +1/+1 counters on each permanent you control that's a creature or Vehicle.

Spectral Shepherd

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

Plains

Absorb

Spectral Sailor

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

Supreme Phantom

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

Spirit Bonds

Whenever a nontoken creature you control enters, you may pay {W}. If you do, create a 1/1 white Spirit creature token with flying.
{1}{W}, Sacrifice a Spirit: Target non-Spirit creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

Patrician Geist

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

Mausoleum Wanderer

Flying
Whenever another Spirit you control enters, 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.

Island

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

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}.

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Selfless Spirit

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

Irrigated Farmland

({T}: Add {W} or {U}.)
Irrigated Farmland enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)