Flash Counter

Unsummon

Return target creature to its owner's hand.

Swamp

Mahamoti Djinn

Flying (This creature can't be blocked except by creatures with flying or reach.)

Remove Soul

Flash Flood

Choose one —
• Destroy target red permanent.
• Return target Mountain to its owner's hand.

Howl from Beyond

Target creature gets +X/+0 until end of turn.

Drudge Skeletons

{B}: Regenerate Drudge Skeletons. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Darkness

Prevent all combat damage that would be dealt this turn.

Air Elemental

Dance of Many

When Dance of Many enters, create a token that's a copy of target nontoken creature.
When Dance of Many leaves the battlefield, exile the token.
When the token leaves the battlefield, sacrifice Dance of Many.
At the beginning of your upkeep, sacrifice Dance of Many unless you pay {U}{U}.

Hymn to Tourach

Target player discards two cards at random.

Gloom

White spells cost {3} more to cast.
Activated abilities of white enchantments cost {3} more to activate.

Drain Life

Spend only black mana on X.
Drain Life deals X damage to any target. You gain life equal to the damage dealt, but not more life than the player's life total before the damage was dealt, the planeswalker's loyalty before the damage was dealt, or the creature's toughness.

Millstone

Control Magic

Enchant creature
You control enchanted creature.

Psychic Venom

Enchant land
Whenever enchanted land becomes tapped, Psychic Venom deals 2 damage to that land's controller.

Old Man of the Sea

You may choose not to untap Old Man of the Sea during your untap step.
{T}: Gain control of target creature with power less than or equal to Old Man of the Sea's power for as long as Old Man of the Sea remains tapped and that creature's power remains less than or equal to Old Man of the Sea's power.

Clockwork Beast

Clockwork Beast enters with seven +1/+0 counters on it.
At end of combat, if Clockwork Beast attacked or blocked this combat, remove a +1/+0 counter from it.
{X}, {T}: Put up to X +1/+0 counters on Clockwork Beast. This ability can't cause the total number of +1/+0 counters on Clockwork Beast to be greater than seven. Activate only during your upkeep.

Boomerang

Return target permanent to its owner's hand.

Juggernaut

This creature attacks each combat if able.
This creature can't be blocked by Walls.

Spirit Shackle

Enchant creature
Whenever enchanted creature becomes tapped, put a -0/-2 counter on it.

Hypnotic Specter

Flying
Whenever Hypnotic Specter deals damage to an opponent, that player discards a card at random.

Library of Alexandria

{T}: Add {C}.
{T}: Draw a card. Activate only if you have exactly seven cards in hand.

Giant Tortoise

Giant Tortoise gets +0/+3 as long as it's untapped.

Strip Mine

{T}: Add {C}.
{T}, Sacrifice Strip Mine: Destroy target land.

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pestilence.
{B}: Pestilence deals 1 damage to each creature and each player.

Gaseous Form

Enchant creature
Prevent all combat damage that would be dealt to and dealt by enchanted creature.

Tolaria

{T}: Add {U}.
{T}: Target creature loses banding and all "bands with other" abilities until end of turn. Activate only during any upkeep step.

Island

Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Staff of Zegon

{3}, {T}: Target creature gets -2/-0 until end of turn.

Ancestral Recall

Prodigal Sorcerer

{T}: Prodigal Sorcerer deals 1 damage to any target.

Ebon Stronghold

Ebon Stronghold enters tapped.
{T}: Add {B}.
{T}, Sacrifice Ebon Stronghold: Add {B}{B}.

Cuombajj Witches

{T}: Cuombajj Witches deals 1 damage to any target and 1 damage to any target of an opponent's choice.

Juzám Djinn

At the beginning of your upkeep, Juzám Djinn deals 1 damage to you.

Spell Blast

Counter target spell with mana value X. (For example, if that spell's mana cost is {3}{U}{U}, X is 5.)

Terror

Destroy target nonartifact, nonblack creature. It can't be regenerated.

Drowned

Water Elemental

Tetravus

Flying
Tetravus enters with three +1/+1 counters on it.
At the beginning of your upkeep, you may remove any number of +1/+1 counters from Tetravus. If you do, create that many 1/1 colorless Tetravite artifact creature tokens. They each have flying and "This creature can't be enchanted."
At the beginning of your upkeep, you may exile any number of tokens created with Tetravus. If you do, put that many +1/+1 counters on Tetravus.