Mental Note

Counterspell

Ice Tunnel

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

Chainer's Edict

Target player sacrifices a creature of their choice.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Consider

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

Thought Scour

Target player mills two cards.
Draw a card.

Island

Cast Down

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}.)

Contaminated Aquifer

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

Disfigure

Target creature gets -2/-2 until end of turn.

Gurmag Angler

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