As Foretold

At the beginning of your upkeep, put a time counter on this enchantment.
Once each turn, you may pay {0} rather than pay the mana cost for a spell you cast with mana value X or less, where X is the number of time counters on this enchantment.

Emergency Powers

Each player shuffles their hand and graveyard into their library, then draws seven cards. Exile Emergency Powers.
Addendum — If you cast this spell during your main phase, you may put a permanent card with mana value 7 or less from your hand onto the battlefield.

Royal Assassin

Day's Undoing

Each player shuffles their hand and graveyard into their library, then draws seven cards. If it's your turn, end the turn. (Exile all spells and abilities from the stack, including this card. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Jace, Unraveler of Secrets

+1: Scry 1, then draw a card.
−2: Return target creature to its owner's hand.
−8: You get an emblem with "Whenever an opponent casts their first spell each turn, counter that spell."

Approach of the Second Sun

If this spell was cast from your hand and you've cast another spell named Approach of the Second Sun this game, you win the game. Otherwise, put Approach of the Second Sun into its owner's library seventh from the top and you gain 7 life.

Plains

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Void Rend

This spell can't be countered.
Destroy target nonland permanent.

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Stinging Study

You draw X cards and you lose X life, where X is the mana value of a commander you own on the battlefield or in the command zone.

Wavebreak Hippocamp

Whenever you cast your first spell during each opponent's turn, draw a card.

Angelic Arbiter

Flying
Each opponent who cast a spell this turn can't attack with creatures.
Each opponent who attacked with a creature this turn can't cast spells.

Teferi, Time Raveler

Each opponent can cast spells only any time they could cast a sorcery.
+1: Until your next turn, you may cast sorcery spells as though they had flash.
−3: Return up to one target artifact, creature, or enchantment to its owner's hand. Draw a card.

Night's Whisper

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Rule of Law

Each player can't cast more than one spell each turn.

Glen Elendra Archmage

Flying
{U}, Sacrifice this creature: Counter target noncreature spell.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Sphinx of the Second Sun

Flying
At the beginning of each of your postcombat main phases, there is an additional beginning phase after this phase. (The beginning phase includes the untap, upkeep, and draw steps.)

Mind's Dilation

Whenever an opponent casts their first spell each turn, that player exiles the top card of their library. If it's a nonland card, you may cast it without paying its mana cost.

Swamp

Temporary Lockdown

When this enchantment enters, exile each nonland permanent with mana value 2 or less until this enchantment leaves the battlefield.

Nimble Larcenist

Flying
When this creature enters, target opponent reveals their hand. You choose an artifact, instant, or sorcery card from it and exile that card.

Diabolic Intent

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card, put that card into your hand, then shuffle.

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Oildeep Gearhulk

Lifelink, ward {1}
When this creature enters, look at target player's hand. You may choose a card from it. If you do, that player discards that card, then draws a card.

Consulate Crackdown

When this enchantment enters, exile all artifacts your opponents control until this enchantment leaves the battlefield.

Island

Negate

Judge's Familiar

Flying
Sacrifice this creature: Counter target instant or sorcery spell unless its controller pays {1}.

Avatar of Woe

If there are ten or more creature cards total in all graveyards, this spell costs {6} less to cast.
Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
{T}: Destroy target creature. It can't be regenerated.

Sin Collector

When this creature enters, target opponent reveals their hand. You choose an instant or sorcery card from it and exile that card.

Consuming Tide

Each player chooses a nonland permanent they control. Return all nonland permanents not chosen this way to their owners' hands. Then you draw a card for each opponent who has more cards in their hand than you.

Eidolon of Rhetoric

Ertai, the Corrupted

{U}, {T}, Sacrifice a creature or enchantment: Counter target spell.

Damping Sphere

If a land is tapped for two or more mana, it produces {C} instead of any other type and amount.
Each spell a player casts costs {1} more to cast for each other spell that player has cast this turn.

Cursecatcher

Sacrifice this creature: Counter target instant or sorcery spell unless its controller pays {1}.

Leyline of Anticipation

If this card is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Shadow of the Second Sun

Enchant player
At the beginning of each of enchanted player's postcombat main phases, there is an additional beginning phase after this phase. (The end step happens after the added untap, upkeep, and draw steps.)

Trinisphere

As long as this artifact is untapped, each spell that would cost less than three mana to cast costs three mana to cast. (Additional mana in the cost may be paid with any color of mana or colorless mana. For example, a spell that would cost {1}{B} to cast costs {2}{B} to cast instead.)

High Fae Trickster

Flash (You may cast this spell any time you could cast an instant.)
Flying
You may cast spells as though they had flash.

Sublime Epiphany

Choose one or more —
• Counter target spell.
• Counter target activated or triggered ability.
• Return target nonland permanent to its owner's hand.
• Create a token that's a copy of target creature you control.
• Target player draws a card.

Vedalken Orrery

You may cast spells as though they had flash.

Vendilion Clique

Flash
Flying
When Vendilion Clique enters, look at target player's hand. You may choose a nonland card from it. If you do, that player reveals the chosen card, puts it on the bottom of their library, then draws a card.

Obscura Charm

Choose one —
• Return target multicolored permanent card with mana value 3 or less from your graveyard to the battlefield tapped.
• Counter target instant or sorcery spell.
• Destroy target creature or planeswalker with mana value 3 or less.

Archon of Emeria

Flying
Each player can't cast more than one spell each turn.
Nonbasic lands your opponents control enter tapped.

Moderation

You can't cast more than one spell each turn.
Whenever you cast a spell, draw a card.

Spell Queller

Flash
Flying
When this creature enters, exile target spell with mana value 4 or less.
When this creature leaves the battlefield, the exiled card's owner may cast that card without paying its mana cost.

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice this land: You may cast spells this turn as though they had flash.