Quick Study

Quench

Counter target spell unless its controller pays {2}.

Psychic Corrosion

Whenever you draw a card, each opponent mills two cards.

Divination

Howling Golem

Whenever this creature attacks or blocks, each player draws a card.

Three Steps Ahead

Spree (Choose one or more additional costs.)
+ {1}{U} — Counter target spell.
+ {3} — Create a token that's a copy of target artifact or creature you control.
+ {2} — Draw two cards, then discard a card.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Blink of an Eye

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Return target nonland permanent to its owner's hand. If this spell was kicked, draw a card.

Island

Diamond Mare

As this creature enters, choose a color.
Whenever you cast a spell of the chosen color, you gain 1 life.

Sleep

Tap all creatures target player controls. Those creatures don't untap during that player's next untap step.

River's Rebuke

Return all nonland permanents target player controls to their owner's hand.

Deduce

Draw a card. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Time of Ice

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Tap target creature an opponent controls. It doesn't untap during its controller's untap step for as long as you control this Saga.
III — Return all tapped creatures to their owners' hands.