Have

Aether Membrane

Defender; reach (This creature can block creatures with flying.)
Whenever Aether Membrane blocks a creature, return that creature to its owner's hand at end of combat.

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Island

Ivory Mask

You have shroud. (You can't be the target of spells or abilities.)

Plains

Furious Resistance

Target blocking creature gets +3/+0 and gains first strike until end of turn.

Mountain

Wall of One Thousand Cuts

Defender, flying
{W}: Wall of One Thousand Cuts can attack this turn as though it didn't have defender.

Dazzling Reflection

You gain life equal to target creature's power. The next time that creature would deal damage this turn, prevent that damage.

Weapon Surge

Target creature you control gets +1/+0 and gains first strike until end of turn.
Overload {1}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Gods Willing

Target creature you control gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)
Scry 1.

Reverberate

Copy target instant or sorcery spell. You may choose new targets for the copy.

Ludevic's Abomination

Ludevic's Test Subject

Defender
{1}{U}: Put a hatchling counter on Ludevic's Test Subject. Then if there are five or more hatchling counters on it, remove all of them and transform it.

Ludevic's Test Subject // Ludevic's Abomination

Wall of Frost

Defender
Whenever Wall of Frost blocks a creature, that creature doesn't untap during its controller's next untap step.

Mnemonic Wall

Defender
When Mnemonic Wall enters, you may return target instant or sorcery card from your graveyard to your hand.

Stalwart Shield-Bearers

Defender
Other creatures you control with defender get +0/+2.

Nivix Cyclops

Defender
Whenever you cast an instant or sorcery spell, Nivix Cyclops gets +3/+0 until end of turn and can attack this turn as though it didn't have defender.

Call the Gatewatch

Search your library for a planeswalker card, reveal it, put it into your hand, then shuffle.

Angelic Wall

Defender (This creature can't attack.)
Flying

Smite

Thunder Strike

Target creature gets +2/+0 and gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Wall of Swords

Chaplain's Blessing

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Fog Bank

Defender, flying
Prevent all combat damage that would be dealt to and dealt by Fog Bank.