Threads of Disloyalty

Enchant creature with mana value 2 or less
You control enchanted creature.

Supreme Phantom

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

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Arcanum Wings

Enchant creature
Enchanted creature has flying.
Aura swap {2}{U} ({2}{U}: Exchange this Aura with an Aura card in your hand.)

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.

Eldrazi Conscription

Enchant creature
Enchanted creature gets +10/+10 and has trample and annihilator 2. (Whenever it attacks, defending player sacrifices two permanents of their choice.)

Rattlechains

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

Plains

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice Curious Obsession.

Aether Gust

Choose target spell or permanent that's red or green. Its owner puts it on their choice of the top or bottom of their library.

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

Nimbus Maze

{T}: Add {C}.
{T}: Add {W}. Activate only if you control an Island.
{T}: Add {U}. Activate only if you control a Plains.

Burrenton Forge-Tender

Protection from red
Sacrifice Burrenton Forge-Tender: Prevent all damage a red source of your choice would deal this turn.

Sky Tether

Enchant creature
Enchanted creature has defender and loses flying.

Sovereigns of Lost Alara

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever a creature you control attacks alone, you may search your library for an Aura card that could enchant that creature, put it onto the battlefield attached to that creature, then shuffle.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Steel of the Godhead

Enchant creature
As long as enchanted creature is white, it gets +1/+1 and has lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)
As long as enchanted creature is blue, it gets +1/+1 and can't be blocked.

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

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}.

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.)

Damping Sphere

If a land is tapped for two or more mana, it produces {C} instead of any other type and amount.
Each spell a player casts costs {1} more to cast for each other spell that player has cast this turn.

Geist of Saint Traft

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Whenever Geist of Saint Traft attacks, create a 4/4 white Angel creature token with flying that's tapped and attacking. Exile that token at end of combat.