Gift of Immortality

Enchant creature
When enchanted creature dies, return that card to the battlefield under its owner's control. Return Gift of Immortality to the battlefield attached to that creature at the beginning of the next end step.

Kor Spiritdancer

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

Nylea's Colossus

Constellation — Whenever Nylea's Colossus or another enchantment you control enters, double target creature's power and toughness until end of turn.

Siona, Captain of the Pyleas

When Siona, Captain of the Pyleas enters, 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.

Octopus Umbra

Enchant creature
Enchanted creature has base power and toughness 8/8 and has "Whenever this creature attacks, you may tap target creature with power 8 or less."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Heliod's Pilgrim

When Heliod's Pilgrim enters, you may search your library for an Aura card, reveal it, put it into your hand, then shuffle.

Spectra Ward

Enchant creature
Enchanted creature gets +2/+2 and has protection from each color. This effect doesn't remove Auras. (It can't be blocked, targeted, or dealt damage by anything that's white, blue, black, red, or green.)

Bruna, Light of Alabaster

Flying, vigilance
Whenever Bruna, Light of Alabaster attacks or blocks, you may attach to it any number of Auras on the battlefield and you may put onto the battlefield attached to it any number of Aura cards that could enchant it from your graveyard and/or hand.

Eldrazi Conscription

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

Herald of the Pantheon

Enchantment spells you cast cost {1} less to cast.
Whenever you cast an enchantment spell, you gain 1 life.

Fertile Ground

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Tuvasa the Sunlit

Tuvasa the Sunlit gets +1/+1 for each enchantment you control.
Whenever you cast your first enchantment spell each turn, draw a card.

Angelic Destiny

Enchant creature
Enchanted creature gets +4/+4, has flying and first strike, and is an Angel in addition to its other types.
When enchanted creature dies, return Angelic Destiny to its owner's hand.

Daybreak Coronet

Enchant creature with another Aura attached to it
Enchanted creature gets +3/+3 and has first strike, vigilance, and lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)

Danitha Capashen, Paragon

First strike, vigilance, lifelink
Aura and Equipment spells you cast cost {1} less to cast.

Eidolon of Countless Battles

Bestow {2}{W}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Eidolon of Countless Battles and enchanted creature each get +1/+1 for each creature you control and +1/+1 for each Aura you control.

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.

Shielded by Faith

Enchant creature
Enchanted creature has indestructible.
Whenever a creature enters, you may attach Shielded by Faith to that creature.

Colossification

Enchant creature
When Colossification enters, tap enchanted creature.
Enchanted creature gets +20/+20.