Moorland Drifter

Delirium — This creature has flying as long as there are four or more card types among cards in your graveyard.

Alhammarret's Archive

If you would gain life, you gain twice that much life instead.
If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Island

Unimpeded Trespasser

Uninvited Geist

Skulk (This creature can't be blocked by creatures with greater power.)
When this creature deals combat damage to a player, transform it.

Uninvited Geist // Unimpeded Trespasser

Tamiyo's Journal

At the beginning of your upkeep, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
{T}, Sacrifice three Clues: Search your library for a card, put that card into your hand, then shuffle.

Plains

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 token: Draw a card.")

Spectral Shepherd

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

Erdwal Illuminator

Flying
Whenever you investigate for the first time each turn, investigate an additional time.

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.

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.

Eerie Interlude

Exile any number of target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

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.

Rattlechains

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

Port Town

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

Apothecary Geist

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

Tower Geist

Flying
When this creature enters, look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.

Topplegeist

Flying
When this creature enters, tap target creature an opponent controls.
Delirium — At the beginning of each opponent's upkeep, if there are four or more card types among cards in your graveyard, tap target creature that player controls.

Emissary of the Sleepless

Flying
When this creature enters, if a creature died this turn, create a 1/1 white Spirit creature token with flying.