Gurmag Angler

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

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}.)

Mental Note

Vapor Snag

Return target creature to its owner's hand. Its controller loses 1 life.

Contaminated Aquifer

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

Thought Scour

Target player mills two cards.
Draw a card.

Cast Down

Brainstorm

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

Ice Tunnel

({T}: Add {U} or {B}.)
Ice Tunnel enters tapped.

Tome Scour

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.)

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Island

Consider

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