Serendib Efreet

Flying
At the beginning of your upkeep, Serendib Efreet deals 1 damage to you.

Flying Men

Force Spike

Counter target spell unless its controller pays {1}.

Lifetap

Whenever a Forest an opponent controls becomes tapped, you gain 1 life.

Unsummon

Return target creature to its owner's hand.

Seasinger

When you control no Islands, sacrifice Seasinger.
You may choose not to untap Seasinger during your untap step.
{T}: Gain control of target creature whose controller controls an Island for as long as you control Seasinger and Seasinger remains tapped.

Phantasmal Terrain

Enchant land
As Phantasmal Terrain enters, choose a basic land type.
Enchanted land is the chosen type.

Psionic Blast

Psionic Blast deals 4 damage to any target and 2 damage to you.

Sunken City

At the beginning of your upkeep, sacrifice Sunken City unless you pay {U}{U}.
Blue creatures get +1/+1.

Dandân

Dandân can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Dandân.

Energy Flux

All artifacts have "At the beginning of your upkeep, sacrifice this artifact unless you pay {2}."

River Merfolk

{U}: River Merfolk gains mountainwalk until end of turn. (It can't be blocked as long as defending player controls a Mountain.)

Braingeyser

Prodigal Sorcerer

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

Sol Ring

Control Magic

Enchant creature
You control enchanted creature.

Lord of Atlantis

Other Merfolk get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

Merfolk of the Pearl Trident

Island

Spell Blast

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

Psychic Purge

Psychic Purge deals 1 damage to any target.
When a spell or ability an opponent controls causes you to discard Psychic Purge, that player loses 5 life.

Recall

Discard X cards, then return a card from your graveyard to your hand for each card discarded this way. Exile Recall.

Counterspell

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Magical Hack

Change the text of target spell or permanent by replacing all instances of one basic land type with another. (For example, you may change "swampwalk" to "plainswalk." This effect lasts indefinitely.)

Time Walk

Chaos Orb

{1}, {T}: If Chaos Orb is on the battlefield, flip Chaos Orb onto the battlefield from a height of at least one foot. If Chaos Orb turns over completely at least once during the flip, destroy all nontoken permanents it touches. Then destroy Chaos Orb.