Thassa's Oracle

When Thassa's Oracle enters, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Crypt Sliver

All Slivers have "{T}: Regenerate target Sliver."

Underground Sea

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Prized Amalgam

Whenever a creature enters, if it entered from your graveyard or you cast it from your graveyard, return Prized Amalgam from your graveyard to the battlefield tapped at the beginning of the next end step.

Bayou

Street Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Cycling—Pay 2 life. (Pay 2 life, Discard this card: Draw a card.)

Shuko

Equipped creature gets +1/+0.
Equip {0} ({0}: Attach to target creature you control. Equip only as a sorcery.)

Mesmeric Orb

Whenever a permanent becomes untapped, that permanent's controller mills a card.

Narcomoeba

Flying
When Narcomoeba is put into your graveyard from your library, you may put it onto the battlefield.

Cephalid Illusionist

Whenever Cephalid Illusionist becomes the target of a spell or ability, mill three cards.
{2}{U}, {T}: Prevent all combat damage that would be dealt to and dealt by target creature you control this turn.

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Tropical Island

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Gustha's Scepter

{T}: Exile a card from your hand face down. You may look at it for as long as it remains exiled.
{T}: Return a card you own exiled with Gustha's Scepter to your hand.
When you lose control of Gustha's Scepter, put all cards exiled with Gustha's Scepter into their owner's graveyard.