The Master of Keys

Flying
When The Master of Keys enters, put X +1/+1 counters on it and mill twice X cards.
Each enchantment card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)

Ajani's Mantra

At the beginning of your upkeep, you may gain 1 life.

Archmage Ascension

At the beginning of each end step, if you drew two or more cards this turn, you may put a quest counter on this enchantment.
As long as this enchantment has six or more quest counters on it, if you would draw a card, you may instead search your library for a card, put that card into your hand, then shuffle.

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

Angelic Chorus

Whenever a creature you control enters, you gain life equal to its toughness.

A Tale for the Ages

Enchanted creatures you control get +2/+2.

Alseid of Life's Bounty

Lifelink
{1}, Sacrifice this creature: Target creature or enchantment you control gains protection from the color of your choice until end of turn.

Agent of the Iron Throne

Commander creatures you own have "Whenever an artifact or creature you control is put into a graveyard from the battlefield, each opponent loses 1 life."

All That Glitters

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