Control Magic

Enchant creature
You control enchanted creature.

Blue Elemental Blast

Choose one —
• Counter target red spell.
• Destroy target red permanent.

Boomerang

Return target permanent to its owner's hand.

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Prodigal Sorcerer

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

Counterspell

Unsummon

Return target creature to its owner's hand.

Phantasmal Terrain

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

Lord of Atlantis

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

Steal Artifact

Enchant artifact
You control enchanted artifact.

Psionic Blast

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

Island

Serendib Efreet

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

Merfolk of the Pearl Trident

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.