Hateful Eidolon

Lifelink
Whenever an enchanted creature dies, draw a card for each Aura you controlled that was attached to it.

Sram, Senior Edificer

Whenever you cast an Aura, Equipment, or Vehicle spell, draw a card.

Kor Spiritdancer

Kor Spiritdancer gets +2/+2 for each Aura attached to it.
Whenever you cast an Aura spell, you may draw a card.

Setessan Champion

Constellation — Whenever an enchantment enters the battlefield under your control, put a +1/+1 counter on Setessan Champion and draw a card.

Tanglespan Lookout

Whenever an Aura enters the battlefield under your control, draw a card.

Siona, Captain of the Pyleas

When Siona, Captain of the Pyleas enters the battlefield, look at the top seven cards of your library. You may reveal an Aura card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Whenever an Aura you control becomes attached to a creature you control, create a 1/1 white Human Soldier creature token.

Ephara, Ever-Sheltering

Ephara, Ever-Sheltering has lifelink and indestructible as long as you control at least three other enchantments.
Whenever another enchantment enters the battlefield under your control, draw a card.

Invasion of Theros

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Theros enters the battlefield, search your library for an Aura, God, or Demigod card, reveal it, put it into your hand, then shuffle.