Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Taigam, Ojutai Master

Instant, sorcery, and Dragon spells you control can't be countered.
Whenever you cast an instant or sorcery spell from your hand, if Taigam, Ojutai Master attacked this turn, that spell gains rebound. (Exile the spell as it resolves. At the beginning of your next upkeep, you may cast that card from exile without paying its mana cost.)

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Shadow Rift

Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)
Draw a card.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Zethi, Arcane Blademaster

Multikicker {W/U}
When Zethi, Arcane Blademaster enters, exile up to X target instant cards from your graveyard, where X is the number of times Zethi was kicked. Put a kick counter on each of them.
Whenever Zethi attacks, copy each exiled card you own with a kick counter on it. You may cast the copies.

Snap

Return target creature to its owner's hand. Untap up to two lands.

Enter the Enigma

Target creature can't be blocked this turn.
Draw a card.

Reset

Cast this spell only during an opponent's turn after their upkeep step.
Untap all lands you control.