Have

Momentary Blink

Exile target creature you control, then return it to the battlefield under its owner's control.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Think Twice

Draw a card.
Flashback {2}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Azorius Guildgate

This land enters tapped.
{T}: Add {W} or {U}.

Unsummon

Return target creature to its owner's hand.

Plains

Island

Saving Grasp

Return target creature you own to your hand.
Flashback {W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Departed Soulkeeper

Flying
Departed Soulkeeper can block only creatures with flying.
If Departed Soulkeeper would be put into a graveyard from anywhere, exile it instead.

Devoted Grafkeeper

When Devoted Grafkeeper enters, mill two cards.
Whenever you cast a spell from your graveyard, tap target creature you don't control.
Disturb {1}{W}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Devoted Grafkeeper // Departed Soulkeeper

Skybridge Towers

Skybridge Towers enters tapped.
{T}: Add {W} or {U}.
{2}{W}{U}, {T}, Sacrifice Skybridge Towers: Draw a card.

Otherworldly Gaze

Surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Otterball Antics

Create a 1/1 blue and red Otter creature token with prowess. If this spell was cast from anywhere other than your hand, put a +1/+1 counter on that creature. (Whenever you cast a noncreature spell, a creature with prowess gets +1/+1 until end of turn.)
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Ominous Roost

When Ominous Roost enters and whenever you cast a spell from your graveyard, create a 1/1 blue Bird creature token with flying and "This creature can block only creatures with flying."

Faithful Mending

You gain 2 life, draw two cards, then discard two cards.
Flashback {1}{W}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Feeling of Dread

Tap up to two target creatures.
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)