Selfless Spirit

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

Entrancing Melody

Gain control of target creature with mana value X.

Oppressive Rays

Enchant creature
Enchanted creature can't attack or block unless its controller pays {3}.
Activated abilities of enchanted creature cost {3} more to activate.

Lurrus of the Dream-Den

Companion — Each permanent card in your starting deck has mana value 2 or less. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Lifelink
Once during each of your turns, you may cast a permanent spell with mana value 2 or less from your graveyard.

Tallowisp

Whenever you cast a Spirit or Arcane spell, you may search your library for an Aura card with enchant creature, reveal it, put it into your hand, then shuffle.

Dorothea's Retribution

Enchant creature
Enchanted creature has "Whenever this creature attacks, create a 4/4 white Spirit creature token with flying that's tapped and attacking. Sacrifice that token at end of combat."
If Dorothea's Retribution would be put into a graveyard from anywhere, exile it instead.

Dorothea, Vengeful Victim

Flying
When Dorothea, Vengeful Victim attacks or blocks, sacrifice it at end of combat.
Disturb {1}{W}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Dorothea, Vengeful Victim // Dorothea's Retribution

Anafenza, Kin-Tree Spirit

Whenever another nontoken creature you control enters, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Unlicensed Hearse

{T}: Exile up to two target cards from a single graveyard.
Unlicensed Hearse's power and toughness are each equal to the number of cards exiled with it.
Crew 2

Supreme Phantom

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

Island

Rattlechains

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

Ethereal Armor

Enchant creature
Enchanted creature gets +1/+1 for each enchantment you control and has first strike.

Hyena Umbra

Enchant creature
Enchanted creature gets +1/+1 and has first strike.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Plains

Seal of Cleansing

Sacrifice Seal of Cleansing: Destroy target artifact or enchantment.

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}.

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.