Eidolon of Rhetoric

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

Drannith Magistrate

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

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.

Archon of Emeria

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

Ethersworn Canonist

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

Winota, Joiner of Forces

Whenever a non-Human creature you control attacks, look at the top six cards of your library. You may put a Human creature card from among them onto the battlefield tapped and attacking. It gains indestructible until end of turn. Put the rest of the cards on the bottom of your library in a random order.

Spirit of the Labyrinth

Each player can't draw more than one card each turn.

Magus of the Moon

Aven Mindcensor

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