Whirlwind Denial

For each spell and ability your opponents control, counter it unless its controller pays {4}.

Thran Power Suit

Equipped creature gets +1/+1 for each Aura and Equipment attached to it and has ward {2}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Take Flight

Enchant creature
Enchanted creature gets +1/+0 and has flying and "Whenever this creature attacks, draw a card."

Mirror Shield

Equipped creature gets +0/+2 and has hexproof and "Whenever a creature with deathtouch blocks or becomes blocked by this creature, destroy that creature."
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

One with the Multiverse

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library.
Once during each of your turns, you may cast a spell from your hand or the top of your library without paying its mana cost.

Assimilate Essence

Counter target creature or battle spell unless its controller pays {4}. If they do, you incubate 2. (Create an Incubator token with two +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)

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.

Concerted Defense

Counter target noncreature spell unless its controller pays {1} plus an additional {1} for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Eel Umbra

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature gets +1/+1.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Scatter Ray

Counter target artifact or creature spell unless its controller pays {4}.

Winged Boots

Equipped creature has flying and ward {4}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
Equip {1}

Kitesail

Equipped creature gets +1/+0 and has flying.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Combat Research

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
As long as enchanted creature is legendary, it gets +1/+1 and has ward {1}. (Whenever enchanted creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Astral Wingspan

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Enchant creature
When Astral Wingspan enters, draw a card.
Enchanted creature gets +2/+2 and has flying.

Semblance Anvil

Imprint — When Semblance Anvil enters, you may exile a nonland card from your hand.
Spells you cast that share a card type with the exiled card cost {2} less to cast.

Fraying Line

When Fraying Line enters, put a rope counter on target creature you control.
At the beginning of each player's upkeep, that player may pay {2}. If they do, they put a rope counter on a creature they control. Otherwise, exile Fraying Line and each creature without a rope counter on it, then remove all rope counters from all creatures.

Mana Leak

Counter target spell unless its controller pays {3}.

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Split the Party

Choose target player. Return half the creatures they control to their owner's hand, rounded up.

Aeronaut's Wings

Don't Have

Negate

Charix, the Raging Isle

Spells your opponents cast that target Charix, the Raging Isle cost {2} more to cast.
{3}: Charix gets +X/-X until end of turn, where X is the number of Islands you control.

Psychic Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, you scry 2.

Island

Flow of Knowledge

Draw a card for each Island you control, then discard two cards.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

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.)

Sol Ring

Masterwork of Ingenuity

You may have Masterwork of Ingenuity enter as a copy of any Equipment on the battlefield.

Artificer's Epiphany

Draw two cards. If you control no artifacts, discard a card.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Jwari Ruins

Jwari Disruption

Counter target spell unless its controller pays {1}.

Jwari Disruption // Jwari Ruins

Shocking Grasp

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

Arcane Signet

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

Convolute

Counter target spell unless its controller pays {4}.

Reenact the Crime

Exile target nonland card in a graveyard that was put there from anywhere this turn. Copy it. You may cast the copy without paying its mana cost.

Spell Pierce

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

Stern Dismissal

Return target creature or enchantment an opponent controls to its owner's hand.

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Teferi, Temporal Archmage

+1: Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.
−1: Untap up to four target permanents.
−10: You get an emblem with "You may activate loyalty abilities of planeswalkers you control on any player's turn any time you could cast an instant."
Teferi, Temporal Archmage can be your commander.

Hero's Heirloom

Equipped creature gets +2/+1.
As long as equipped creature is legendary, it has trample and haste.
Equip {2}

Security Bypass

Enchant creature
As long as enchanted creature is attacking alone, it can't be blocked.
Enchanted creature has "Whenever this creature deals combat damage to a player, it connives." (Its controller draws a card, then discards a card. If they discarded a nonland card, they put a +1/+1 counter on this creature.)

Cliffhaven Kitesail

When Cliffhaven Kitesail enters, attach it to target creature you control.
Equipped creature has flying.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Short Circuit

Flash
Enchant artifact or creature
As long as enchanted permanent is a creature, it gets -3/-0 and loses flying.

Modify Memory

Exchange control of two target creatures controlled by different players. If you control neither creature, draw three cards.