Niv-Mizzet, Visionary

Flying
You have no maximum hand size.
Whenever a source you control deals noncombat damage to an opponent, you draw that many cards.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Blue Sun's Twilight

Gain control of target creature with mana value X or less. If X is 5 or more, create a token that's a copy of that creature.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Bonded Fetch

Defender, haste
{T}: Draw a card, then discard a card.

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Betrayal

Enchant creature an opponent controls
Whenever enchanted creature becomes tapped, you draw a card.

Niv-Mizzet, the Firemind

Flying
Whenever you draw a card, Niv-Mizzet deals 1 damage to any target.
{T}: Draw a card.

Jin-Gitaxias, Core Augur

Flash
At the beginning of your end step, draw seven cards.
Each opponent's maximum hand size is reduced by seven.

Disallow

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Alchemist's Retrieval

Cleave {1}{U} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Return target nonland permanent [you control] to its owner's hand.

Borrowing 100,000 Arrows

Draw a card for each tapped creature target opponent controls.

Admiral's Order

Raid — If you attacked this turn, you may pay {U} rather than pay this spell's mana cost.
Counter target spell.

Acquire

Search target opponent's library for an artifact card and put that card onto the battlefield under your control. Then that player shuffles.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Call to Mind

Return target instant or sorcery card from your graveyard to your hand.

Convolute

Counter target spell unless its controller pays {4}.

Iron Man, Titan of Innovation

Flying, haste
Genius Industrialist — Whenever Iron Man attacks, create a Treasure token, then you may sacrifice a noncreature artifact. If you do, search your library for an artifact card with mana value equal to 1 plus the sacrificed artifact's mana value, put it onto the battlefield tapped, then shuffle.

Fork

Copy target instant or sorcery spell, except that the copy is red. You may choose new targets for the copy.

Alphinaud Leveilleur

Partner with Alisaie Leveilleur (When this creature enters, target player may put Alisaie Leveilleur into their hand from their library, then shuffle.)
Vigilance
Eukrasia — Whenever you cast your second spell each turn, draw a card.

Niv-Mizzet, Dracogenius

Flying
Whenever Niv-Mizzet deals damage to a player, you may draw a card.
{U}{R}: Niv-Mizzet deals 1 damage to any target.

Dissolve

Counter target spell. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Act of Aggression

({R/P} can be paid with either {R} or 2 life.)
Gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Niv-Mizzet, Parun

This spell can't be countered.
Flying
Whenever you draw a card, Niv-Mizzet deals 1 damage to any target.
Whenever a player casts an instant or sorcery spell, you draw a card.

Acidic Soil

Acidic Soil deals damage to each player equal to the number of lands they control.