Cackling Counterpart

Create a token that's a copy of target creature you control.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Silent Departure

Return target creature to its owner's hand.
Flashback {4}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sensory Deprivation

Enchant creature
Enchanted creature gets -3/-0.

Ludevic's Abomination

Ludevic's Test Subject

Defender
{1}{U}: Put a hatchling counter on Ludevic's Test Subject. Then if there are five or more hatchling counters on it, remove all of them and transform it.

Ludevic's Test Subject // Ludevic's Abomination

Spectral Rider

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Ghostly Possession

Enchant creature
Enchanted creature has flying.
Prevent all combat damage that would be dealt to and dealt by enchanted creature.

Deranged Assistant

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Island

Midnight Haunting

Create two 1/1 white Spirit creature tokens with flying.

One-Eyed Scarecrow

Defender
Creatures with flying your opponents control get -1/-0.

Galvanic Juggernaut

Galvanic Juggernaut attacks each combat if able.
Galvanic Juggernaut doesn't untap during your untap step.
Whenever another creature dies, untap Galvanic Juggernaut.

Moon Heron

Lantern Spirit

Flying
{U}: Return Lantern Spirit to its owner's hand.

Claustrophobia

Enchant creature
When Claustrophobia enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Plains

Chapel Geist

Doomed Traveler

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

Voiceless Spirit

Battleground Geist

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

Sturmgeist

Flying
Sturmgeist's power and toughness are each equal to the number of cards in your hand.
Whenever Sturmgeist deals combat damage to a player, draw a card.