Aven Mindcensor

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

Archivist of Oghma

Flash
Whenever an opponent searches their library, you gain 1 life and draw a card.

Nova Cleric

{2}{W}, {T}, Sacrifice Nova Cleric: Destroy all enchantments.

Ethersworn Canonist

Each player who has cast a nonartifact spell this turn can't cast additional nonartifact spells.

Drannith Magistrate

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

Custodi Soulcaller

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Whenever Custodi Soulcaller attacks, return target creature card with mana value X or less from your graveyard to the battlefield, where X is the number of players you attacked this combat.

Strict Proctor

Flying
Whenever a permanent entering causes a triggered ability to trigger, counter that ability unless its controller pays {2}.

Slate Street Ruffian

Whenever Slate Street Ruffian becomes blocked, defending player discards a card.

Nalia de'Arnise

You may look at the top card of your library any time.
You may cast Cleric, Rogue, Warrior, and Wizard spells from the top of your library.
At the beginning of combat on your turn, if you have a full party, put a +1/+1 counter on each creature you control and those creatures gain deathtouch until end of turn.

Leonin Arbiter

Players can't search libraries. Any player may pay {2} for that player to ignore this effect until end of turn.

Dreamstealer

Menace
Whenever Dreamstealer deals combat damage to a player, that player discards that many cards.
Eternalize {4}{B}{B} ({4}{B}{B}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Human Wizard with no mana cost. Eternalize only as a sorcery.)

Grand Abolisher

During your turn, your opponents can't cast spells or activate abilities of artifacts, creatures, or enchantments.

Merciless Executioner

When Merciless Executioner enters, each player sacrifices a creature of their choice.