Manglehorn

When this creature enters, you may destroy target artifact.
Artifacts your opponents control enter tapped.

Ground Seal

When this enchantment enters, draw a card.
Cards in graveyards can't be the targets of spells or abilities.

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.

World Queller

At the beginning of your upkeep, you may choose a card type. If you do, each player sacrifices a permanent of their choice of that type.

Monastery Siege

As this enchantment enters, choose Khans or Dragons.
• Khans — At the beginning of your draw step, draw an additional card, then discard a card.
• Dragons — Spells your opponents cast that target you or a permanent you control cost {2} more to cast.

Fertile Ground

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Kismet

Artifacts, creatures, and lands your opponents control enter tapped.

Rule of Law

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

Deafening Silence

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

Reprobation

Enchant creature
Enchanted creature loses all abilities and is a Coward creature with base power and toughness 0/1. (It keeps all supertypes but loses all other types and creature types.)

Arasta of the Endless Web

Reach
Whenever an opponent casts an instant or sorcery spell, create a 1/2 green Spider creature token with reach.

Containment Priest

Flash
If a nontoken creature would enter and it wasn't cast, exile it instead.

Frozen Aether

Estrid, the Masked

+2: Untap each enchanted permanent you control.
−1: Create a white Aura enchantment token named Mask attached to another target permanent. The token has enchant permanent and umbra armor.
−7: Mill seven cards. Return all non-Aura enchantment cards from your graveyard to the battlefield, then do the same for Aura cards.
Estrid, the Masked can be your commander.

Ghostly Prison

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

Archon of Valor's Reach

Flying, vigilance, trample
As this creature enters, choose artifact, enchantment, instant, sorcery, or planeswalker.
Players can't cast spells of the chosen type.

Fall of the Thran

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy all lands.
II, III — Each player returns two land cards from their graveyard to the battlefield.

Hushwing Gryff

Flash
Flying
Creatures entering don't cause abilities to trigger.

Hushbringer

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

Kasmina, Enigmatic Mentor

Spells your opponents cast that target a creature or planeswalker you control cost {2} more to cast.
−2: Create a 2/2 blue Wizard creature token. Draw a card, then discard a card.

Cursed Totem

Activated abilities of creatures can't be activated.

Vryn Wingmare

Flying
Noncreature spells cost {1} more to cast.

Windborn Muse

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

Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Curator's Ward

Enchant permanent
Enchanted permanent has hexproof.
When enchanted permanent leaves the battlefield, if it was historic, draw two cards. (Artifacts, legendaries, and Sagas are historic.)