Mystical Dispute

This spell costs {2} less to cast if it targets a blue spell.
Counter target spell unless its controller pays {3}.

Isolate

Exile target permanent with mana value 1.

Devout Decree

Exile target creature or planeswalker that's black or red. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Watcher of the Spheres

Flying
Creature spells with flying you cast cost {1} less to cast.
Whenever another creature you control with flying enters, Watcher of the Spheres gets +1/+1 until end of turn.

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Nebelgast Herald

Flash (You may cast this spell any time you could cast an instant.)
Flying
Whenever Nebelgast Herald or another Spirit you control enters, tap target creature an opponent controls.

Avacyn, the Purifier

Flying
When this creature transforms into Avacyn, the Purifier, it deals 3 damage to each other creature and each opponent.

Archangel Avacyn

Flash
Flying, vigilance
When Archangel Avacyn enters, creatures you control gain indestructible until end of turn.
When a non-Angel creature you control dies, transform Archangel Avacyn at the beginning of the next upkeep.

Archangel Avacyn // Avacyn, the Purifier

Supreme Phantom

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

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.

Plains

Beckon Apparition

Exile target card from a graveyard. Create a 1/1 white and black Spirit creature token with flying.

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

Island

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Lofty Denial

Counter target spell unless its controller pays {1}. If you control a creature with flying, counter that spell unless its controller pays {4} instead.

Light of Hope

Choose one —
• You gain 4 life.
• Destroy target enchantment.
• Put a +1/+1 counter on target creature.

Rattlechains

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

Glacial Fortress

Glacial Fortress enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Dovin's Veto

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

Shacklegeist

Flying
Shacklegeist can block only creatures with flying.
Tap two untapped Spirits you control: Tap target creature you don't control.

Selfless Spirit

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

Spell Queller

Flash
Flying
When Spell Queller enters, exile target spell with mana value 4 or less.
When Spell Queller leaves the battlefield, the exiled card's owner may cast that card without paying its mana cost.

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.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.