Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Tolarian Terror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Arms of Hadar

Creatures target player controls get -2/-2 until end of turn.

Counterspell

Swamp

Island

Lose Focus

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Counter target spell unless its controller pays {2}.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Sultai Scavenger

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Flying

Contaminated Aquifer

({T}: Add {U} or {B}.)
Contaminated Aquifer enters tapped.

Pharika's Libation

Choose one —
• Target opponent sacrifices a creature of their choice.
• Target opponent sacrifices an enchantment of their choice.

Blue Elemental Blast

Choose one —
• Counter target red spell.
• Destroy target red permanent.

Insectile Aberration

Delver of Secrets

At the beginning of your upkeep, look at the top card of your library. You may reveal that card. If an instant or sorcery card is revealed this way, transform Delver of Secrets.

Delver of Secrets // Insectile Aberration

Nihil Spellbomb

{T}, Sacrifice Nihil Spellbomb: Exile target player's graveyard.
When Nihil Spellbomb is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

Cast Down

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)