Topplegeist

Flying
When Topplegeist 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.

Furtive Homunculus

Skulk (This creature can't be blocked by creatures with greater power.)

Dauntless Cathar

{1}{W}, Exile Dauntless Cathar from your graveyard: Create a 1/1 white Spirit creature token with flying. Activate only as a sorcery.

Gone Missing

Put target permanent on top of its owner's library.
Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Expose Evil

Tap up to two target creatures.
Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Stern Constable

{T}, Discard a card: Tap target creature.

Spectral Shepherd

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

Press for Answers

Tap target creature. It doesn't untap during its controller's next untap step.
Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Angel of Deliverance

Flying
Delirium — Whenever Angel of Deliverance deals damage, if there are four or more card types among cards in your graveyard, exile target creature an opponent controls.

Vessel of Ephemera

{2}{W}, Sacrifice Vessel of Ephemera: Create two 1/1 white Spirit creature tokens with flying.

Island

Catalog

Niblis of Dusk

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Emissary of the Sleepless

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

Plains

Apothecary Geist

Flying
When Apothecary Geist enters, if you control another Spirit, you gain 3 life.

Ghostly Wings

Enchant creature
Enchanted creature gets +1/+1 and has flying.
Discard a card: Return enchanted creature to its owner's hand.