Timetwister

Each player shuffles their hand and graveyard into their library, then draws seven cards. (Then put Timetwister into its owner's graveyard.)

Boomerang

Return target permanent to its owner's hand.

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.

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.

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Unsummon

Return target creature to its owner's hand.

Counterspell

Island

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.

Strip Mine

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

Psychic Venom

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

Serendib Efreet

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

Mana Vault

Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

Lord of Atlantis

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

Ancestral Recall

Clone

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

Sol Ring

Time Walk

Mox Jet

Mahamoti Djinn

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

Mox Sapphire

Merfolk of the Pearl Trident

Braingeyser

River Merfolk

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

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.

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.

Force Spike

Counter target spell unless its controller pays {1}.

Svyelunite Temple

Svyelunite Temple enters tapped.
{T}: Add {U}.
{T}, Sacrifice Svyelunite Temple: Add {U}{U}.

Recall

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