Divination

Pact of Negation

Counter target spell.
At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

Island

Thassa's Oracle

When this creature 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.)

Lightning Greaves

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

Mana Severance

Search your library for any number of land cards, exile them, then shuffle.

Kaho, Minamo Historian

When Kaho enters, search your library for up to three instant cards, exile them, then shuffle.
{X}, {T}: You may cast a spell with mana value X from among cards exiled with Kaho without paying its mana cost.