Rule of Law

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

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}.

Grand Arbiter Augustin IV

White spells you cast cost {1} less to cast.
Blue spells you cast cost {1} less to cast.
Spells your opponents cast cost {1} more to cast.

Narset, Parter of Veils

Each opponent can't draw more than one card each turn.
−2: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Fatespinner

At the beginning of each opponent's upkeep, that player chooses draw step, main phase, or combat phase. The player skips each instance of the chosen step or phase this turn.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. Talisman of Progress deals 1 damage to you.

Misleading Signpost

Flash
When Misleading Signpost enters during the declare attackers step, you may reselect which player or permanent target attacking creature is attacking. (It can't attack its controller or their permanents.)
{T}: Add {U}.

Sun Titan

Vigilance
Whenever Sun Titan enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Arcane Signet

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

Suppression Field

Activated abilities cost {2} more to activate unless they're mana abilities.

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.

Sol Ring

Rhystic Study

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

Azorius Signet

Elspeth Conquers Death

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Exile target permanent an opponent controls with mana value 3 or greater.
II — Noncreature spells your opponents cast cost {2} more to cast until your next turn.
III — Return target creature or planeswalker card from your graveyard to the battlefield. Put a +1/+1 counter or a loyalty counter on it.

Drannith Magistrate

Your opponents can't cast spells from anywhere other than their hands.

Karn, the Great Creator

Activated abilities of artifacts your opponents control can't be activated.
+1: Until your next turn, up to one target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value.
−2: You may reveal an artifact card you own from outside the game or choose a face-up artifact card you own in exile. Put that card into your hand.

Academy Loremaster

At the beginning of each player's draw step, that player may draw an additional card. If they do, spells they cast this turn cost {2} more to cast.

Ghostly Prison

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

God-Pharaoh's Statue

Spells your opponents cast cost {2} more to cast.
At the beginning of your end step, each opponent loses 1 life.

Hushbringer

Flying, lifelink
Creatures entering or dying don't cause abilities to trigger.

Aven Mindcensor

Flash
Flying
If an opponent would search a library, that player searches the top four cards of that library instead.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Spelltithe Enforcer

Whenever an opponent casts a spell, that player sacrifices a permanent of their choice unless they pay {1}.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Dovin Baan

+1: Until your next turn, up to one target creature gets -3/-0 and its activated abilities can't be activated.
−1: You gain 2 life and draw a card.
−7: You get an emblem with "Your opponents can't untap more than two permanents during their untap steps."

Ojutai's Command

Choose two —
• Return target creature card with mana value 2 or less from your graveyard to the battlefield.
• You gain 4 life.
• Counter target creature spell.
• Draw a card.

Teferi, Hero of Dominaria

+1: Draw a card. At the beginning of the next end step, untap up to two lands.
−3: Put target nonland permanent into its owner's library third from the top.
−8: You get an emblem with "Whenever you draw a card, exile target permanent an opponent controls."

Propaganda

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Dovin, Hand of Control

Artifact, instant, and sorcery spells your opponents cast cost {1} more to cast.
−1: Until your next turn, prevent all damage that would be dealt to and dealt by target permanent an opponent controls.

Aura of Silence

Artifact and enchantment spells your opponents cast cost {2} more to cast.
Sacrifice Aura of Silence: Destroy target artifact or enchantment.