Battleground Geist

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

Cloudstone Curio

Whenever a nonartifact permanent you control enters, you may return another permanent you control that shares a permanent type with it to its owner's hand.

Dream Stalker

When Dream Stalker enters, return a permanent you control to its owner's hand.

Rattlechains

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

Apothecary Geist

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

Equilibrium

Whenever you cast a creature spell, you may pay {1}. If you do, return target creature to its owner's hand.

Angelic Curator

Angelic Page

Flying
{T}: Target attacking or blocking creature gets +1/+1 until end of turn.

Ageless Guardian

Blinking Spirit

{0}: Return Blinking Spirit to its owner's hand.

Sunken Hope

At the beginning of each player's upkeep, that player returns a creature they control to its owner's hand.

Azorius Herald

Azorius Herald can't be blocked.
When Azorius Herald enters, you gain 4 life.
When Azorius Herald enters, sacrifice it unless {U} was spent to cast it.

Crystal Shard

{3}, {T} or {U}, {T}: Return target creature to its owner's hand unless its controller pays {1}.

Benevolent Ancestor

Defender (This creature can't attack.)
{T}: Prevent the next 1 damage that would be dealt to any target this turn.