Neheb, Dreadhorde Champion

Trample
Whenever Neheb deals combat damage to a player or planeswalker, you may discard any number of cards. If you do, draw that many cards and add that much {R}. Until end of turn, you don't lose this mana as steps and phases end.

Surly Badgersaur

Whenever you discard a creature card, put a +1/+1 counter on this creature.
Whenever you discard a land card, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Whenever you discard a noncreature, nonland card, this creature fights up to one target creature you don't control.

Diamond Lion

{T}, Discard your hand, Sacrifice this creature: Add three mana of any one color. Activate only as an instant.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Drake Haven

Whenever you cycle or discard a card, you may pay {1}. If you do, create a 2/2 blue Drake creature token with flying.

Treasure Cruise

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

Careful Study

Haughty Djinn

Flying
Haughty Djinn's power is equal to the number of instant and sorcery cards in your graveyard.
Instant and sorcery spells you cast cost {1} less to cast.

Glint-Horn Buccaneer

Haste
Whenever you discard a card, this creature deals 1 damage to each opponent.
{1}{R}, Discard a card: Draw a card. Activate only if this creature is attacking.

Fists of Flame

Draw a card. Until end of turn, target creature gains trample and gets +1/+0 for each card you've drawn this turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Magus of the Bazaar

{T}: Draw two cards, then discard three cards.

Bedlam Reveler

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, discard your hand, then draw three cards.

Brallin, Skyshark Rider

Partner with Shabraz, the Skyshark (When this creature enters, target player may put Shabraz into their hand from their library, then shuffle.)
Whenever you discard a card, put a +1/+1 counter on Brallin and it deals 1 damage to each opponent.
{R}: Target Shark gains trample until end of turn.

Recall

Discard X cards, then return a card from your graveyard to your hand for each card discarded this way. Exile Recall.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Change of Fortune

Discard your hand, then draw a card for each card you've discarded this turn.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Collective Defiance

Escalate {1} (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Target player discards all the cards in their hand, then draws that many cards.
• Collective Defiance deals 4 damage to target creature.
• Collective Defiance deals 3 damage to target opponent or planeswalker.

Harmonic Prodigy

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
If an ability of a Shaman or another Wizard you control triggers, that ability triggers an additional time.

Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Toothy, Imaginary Friend

Partner with Pir, Imaginative Rascal (When this creature enters, target player may put Pir into their hand from their library, then shuffle.)
Whenever you draw a card, put a +1/+1 counter on Toothy.
When Toothy leaves the battlefield, draw a card for each +1/+1 counter on it.

Counterspell

Mishra's Command

Choose two —
• Choose target player. They may discard up to X cards. Then they draw a card for each card discarded this way.
• This spell deals X damage to target creature.
• This spell deals X damage to target planeswalker.
• Target creature gets +X/+0 and gains haste until end of turn.

Shattered Perception

Discard all the cards in your hand, then draw that many cards.
Flashback {5}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

Rielle, the Everwise

Rielle gets +1/+0 for each instant and sorcery card in your graveyard.
Whenever you discard one or more cards for the first time each turn, draw that many cards.

Cathartic Pyre

Choose one —
• Cathartic Pyre deals 3 damage to target creature or planeswalker.
• Discard up to two cards, then draw that many cards.

Tolarian Winds

Discard all the cards in your hand, then draw that many cards.

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Triskaidekaphile

You have no maximum hand size.
At the beginning of your upkeep, if you have exactly thirteen cards in your hand, you win the game.
{3}{U}: Draw a card.

Containment Construct

Whenever you discard a card, you may exile that card from your graveyard. If you do, you may play that card this turn.

Conspiracy Theorist

Whenever this creature attacks, you may pay {1} and discard a card. If you do, draw a card.
Whenever you discard one or more nonland cards, you may exile one of them from your graveyard. If you do, you may cast it this turn.

Library of Leng

You have no maximum hand size.
If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.

Forbid

Buyback—Discard two cards. (You may discard two cards in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Counter target spell.

Teferi's Ageless Insight

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Nahiri's Wrath

As an additional cost to cast this spell, discard X cards.
Nahiri's Wrath deals damage equal to the total mana value of the discarded cards to each of up to X target creatures and/or planeswalkers.

Negate

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Dangerous Wager

Read the Runes

Draw X cards. For each card drawn this way, discard a card unless you sacrifice a permanent.

Turbulent Dreams

As an additional cost to cast this spell, discard X cards.
Return X target nonland permanents to their owners' hands.

Breakthrough

Draw four cards, then choose X cards in your hand and discard the rest.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Channeled Force

As an additional cost to cast this spell, discard X cards.
Target player draws X cards. Channeled Force deals X damage to up to one target creature or planeswalker.

Foil

You may discard an Island card and another card rather than pay this spell's mana cost.
Counter target spell.

Ominous Seas

Whenever you draw a card, put a foreshadow counter on this enchantment.
Remove eight foreshadow counters from this enchantment: Create an 8/8 blue Kraken creature token.
Cycling {2} ({2}, Discard this card: Draw a card.)

Magus of the Wheel

{1}{R}, {T}, Sacrifice this creature: Each player discards their hand, then draws seven cards.

Ledger Shredder

Flying
Whenever a player casts their second spell each turn, this creature connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Brainstorm

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

Tormenting Voice

Fateful Showdown

Fateful Showdown deals damage to any target equal to the number of cards in your hand. Discard all the cards in your hand, then draw that many cards.

Sol Ring

Battlewing Mystic

Kicker {R} (You may pay an additional {R} as you cast this spell.)
Flying
When this creature enters, if it was kicked, discard your hand, then draw two cards.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Cathartic Reunion

As an additional cost to cast this spell, discard two cards.
Draw three cards.

Jace's Archivist

{U}, {T}: Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Izzet Charm

Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• Izzet Charm deals 2 damage to target creature.
• Draw two cards, then discard two cards.

Ideas Unbound

Draw three cards. Discard three cards at the beginning of the next end step.

Rites of Refusal

Discard any number of cards. Counter target spell unless its controller pays {3} for each card discarded this way.

Island

Thassa's Oracle

When this creature enters, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Mountain

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.)