Answered Prayers

Whenever a creature you control enters, you gain 1 life. If Answered Prayers isn't a creature, it becomes a 3/3 Angel creature with flying in addition to its other types until end of turn.

Plains

Flicker of Fate

Exile target creature or enchantment, then return it to the battlefield under its owner's control.

Stalwart Valkyrie

You may pay {1}{W} and exile a creature card from your graveyard rather than pay this spell's mana cost.
Flying

Anointer of Valor

Flying
Whenever a creature attacks, you may pay {3}. When you do, put a +1/+1 counter on that creature.

Call to Serve

Enchant nonblack creature
Enchanted creature gets +1/+2, has flying, and is an Angel in addition to its other types.

Celestial Unicorn

Whenever you gain life, put a +1/+1 counter on Celestial Unicorn.

Segovian Angel

Aerial Assault

Destroy target tapped creature. You gain 1 life for each creature you control with flying.

Seraph Sanctuary

When Seraph Sanctuary enters, you gain 1 life.
Whenever an Angel you control enters, you gain 1 life.
{T}: Add {C}.

Angelic Page

Flying
{T}: Target attacking or blocking creature gets +1/+1 until end of turn.

Inspiring Overseer

Flying
When this creature enters, you gain 1 life and draw a card.

Scroll of Avacyn

{1}, Sacrifice Scroll of Avacyn: Draw a card. If you control an Angel, you gain 5 life.

Voice of the Provinces

Flying
When Voice of the Provinces enters, create a 1/1 white Human creature token.

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Bladed Bracers

Equipped creature gets +1/+1.
As long as equipped creature is a Human or an Angel, it has vigilance.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)