Aven Mindcensor

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

Thalia, Heretic Cathar

First strike
Creatures and nonbasic lands your opponents control enter tapped.

Creature cards in graveyards and libraries can't enter the battlefield.
Players can't cast spells from graveyards or libraries.

Creatures entering don't cause abilities to trigger.

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.

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

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

As Meddling Mage enters, choose a nonland card name.
Spells with the chosen name can't be cast.