Asha's Favor

Enchant creature
Enchanted creature has flying, first strike, and vigilance.

Battle Mastery

Enchant creature
Enchanted creature has double strike. (It deals both first-strike and regular combat damage.)

Eriette, the Beguiler

Lifelink
Whenever an Aura you control becomes attached to a nonland permanent an opponent controls with mana value less than or equal to that Aura's mana value, gain control of that permanent for as long as that Aura is attached to it.

Aspect of Lamprey

Enchant creature you control
When this Aura enters, target opponent discards two cards.
Enchanted creature has lifelink.

Aerial Modification

Enchant creature or Vehicle
As long as enchanted permanent is a Vehicle, it's a creature in addition to its other types.
Enchanted creature gets +2/+2 and has flying.

Aspect of Gorgon

Enchant creature
Enchanted creature gets +1/+3 and has deathtouch. (Any amount of damage it deals to a creature is enough to destroy it.)

All That Glitters

Enchant creature
Enchanted creature gets +1/+1 for each artifact and/or enchantment you control.

Auramancer's Guise

Enchant creature
Enchanted creature gets +2/+2 for each Aura attached to it and has vigilance.