Time Walk

Black Vise

As Black Vise enters, choose an opponent.
At the beginning of the chosen player's upkeep, Black Vise deals X damage to that player, where X is the number of cards in their hand minus 4.

Tropical Island

Lord of Atlantis

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

Mox Emerald

Braingeyser

Ancestral Recall

Mana Short

Tap all lands target player controls and that player loses all unspent mana.

Mox Sapphire

Giant Growth

Target creature gets +3/+3 until end of turn.

Black Lotus

{T}, Sacrifice Black Lotus: Add three mana of any one color.

Merfolk of the Pearl Trident

Unsummon

Return target creature to its owner's hand.

Counterspell

Channel

Until end of turn, any time you could activate a mana ability, you may pay 1 life. If you do, add {C}.