Mana Leak

Counter target spell unless its controller pays {3}.

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Spectral Procession

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

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.

Call to the Kindred

Enchant creature
At the beginning of your upkeep, you may look at the top five cards of your library. If you do, you may put a creature card that shares a creature type with enchanted creature from among them onto the battlefield, then you put the rest of those cards on the bottom of your library in any order.

Supreme Phantom

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

Drogskol Captain

Flying
Other Spirit creatures you control get +1/+1 and have hexproof. (They can't be the targets of spells or abilities your opponents control.)