Lier, Disciple of the Drowned

Spells can't be countered.
Each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost.

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.)

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Out of the Way

This spell costs {2} less to cast if it targets a green permanent.
Return target nonland permanent an opponent controls to its owner's hand.
Draw a card.

No Escape

Counter target creature or planeswalker spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.
Scry 1.

Stealth Mission

Put two +1/+1 counters on target creature you control. That creature can't be blocked this turn.

Discover the Impossible

Look at the top five cards of your library. Exile one of them face down and put the rest on the bottom of your library in a random order. You may cast the exiled card without paying its mana cost if it's an instant spell with mana value 2 or less. If you don't, put that card into your hand.

Invoke the Winds

Gain control of target artifact or creature. Untap it.

Defiler of Dreams

Flying
As an additional cost to cast blue permanent spells, you may pay 2 life. Those spells cost {U} less to cast if you paid life this way. This effect reduces only the amount of blue mana you pay.
Whenever you cast a blue permanent spell, draw a card.

Mesmeric Glare

Counter target spell with mana value 3 or less. (Then exile this card. You may cast the creature later from exile.)

Hypnotic Sprite

Hypnotic Sprite // Mesmeric Glare

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Negate

Pixie Dust

Up to three target creatures gain flying until end of turn. (Then exile this card. You may cast the creature later from exile.)

Moonshae Pixie

Flying
When this creature enters, draw cards equal to the number of opponents who were dealt combat damage this turn.

Moonshae Pixie // Pixie Dust

Divination

Founding the Third Path

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — You may cast an instant or sorcery spell with mana value 1 or 2 from your hand without paying its mana cost.
II — Target player mills four cards.
III — Exile target instant or sorcery card from your graveyard. Copy it. You may cast the copy.

Catalog

Tome Scour

Miscast

Counter target instant or sorcery spell unless its controller pays {3}.

Choking Tethers

Tap up to four target creatures.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle this card, you may tap target creature.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Serpentine Ambush

Until end of turn, target creature becomes a blue Serpent with base power and toughness 5/5.

You Come to a River

Choose one —
• Fight the Current — Return target nonland permanent to its owner's hand.
• Find a Crossing — Target creature gets +1/+0 until end of turn and can't be blocked this turn.

The Magic Mirror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
You have no maximum hand size.
At the beginning of your upkeep, put a knowledge counter on The Magic Mirror, then draw a card for each knowledge counter on The Magic Mirror.

Sudden Insight

Draw a card for each different mana value among nonland cards in your graveyard.

Curate

Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Draw a card.

Chain to Memory

Target creature gets -4/-0 until end of turn. Scry 2.

Sift

Portent

Look at the top three cards of target player's library, then put them back in any order. You may have that player shuffle.
Draw a card at the beginning of the next turn's upkeep.

Primal Wellspring

(Transforms from Primal Amulet.)
{T}: Add one mana of any color. When that mana is spent to cast an instant or sorcery spell, copy that spell and you may choose new targets for the copy.

Primal Amulet

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, put a charge counter on this artifact. Then if there are four or more charge counters on it, you may remove those counters and transform it.

Primal Amulet // Primal Wellspring

Vodalian Arcanist

{T}: Add {C}. Spend this mana only to cast an instant or sorcery spell.

Thought Collapse

Counter target spell. Its controller mills three cards.

Wizard Class

(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

Shocking Grasp

Target creature gets -2/-0 until end of turn.
Draw a card.

Suit Up

Until end of turn, target creature or Vehicle becomes an artifact creature with base power and toughness 4/5.
Draw a card.

Stormchaser Drake

Flying
Whenever this creature becomes the target of a spell you control, draw a card.

Jace's Sanctum

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, scry 1.

Precognitive Perception

Draw three cards.
Addendum — If you cast this spell during your main phase, instead scry 3, then draw three cards.

Esior, Wardwing Familiar

Flying
Spells your opponents cast that target one or more commanders you control cost {3} more to cast.
Partner (You can have two commanders if both have partner.)

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Syncopate

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Essence Scatter

Volshe Tideturner

{T}: Add {U}. Spend this mana only to cast an instant or sorcery spell or a kicked spell.

Sudden Storm

Tap up to two target creatures. Those creatures don't untap during their controllers' next untap steps. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Case the Joint

Draw two cards, then look at the top card of each player's library.

Gale, Waterdeep Prodigy

Whenever you cast an instant or sorcery spell from your hand, you may cast up to one target card of the other type from your graveyard. If a spell cast from your graveyard this way would be put into your graveyard, exile it instead.
Choose a Background (You can have a Background as a second commander.)

Shimmer of Possibility

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in a random order.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Whispering Wizard

Whenever you cast a noncreature spell, create a 1/1 white Spirit creature token with flying. This ability triggers only once each turn.

Rookie Mistake

Until end of turn, target creature gets +0/+2 and another target creature gets -2/-0.