Yakotakos

Theros's human philosophers were at a marked disadvantage due to their need to pause for things like food or sleep.

Eidolon of Rhetoric

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

A glimpse into a life of fun and friendship.

Tigereye Cameo

Estinien Varlineau

Whenever you cast a noncreature spell, put a +1/+1 counter on Estinien Varlineau. It gains flying until end of turn.
At the beginning of your second main phase, you draw X cards and lose X life, where X is the number of your opponents who were dealt combat damage by Estinien Varlineau or a Dragon this turn.

Hylda of the Icy Crown

Whenever you tap an untapped creature an opponent controls, you may pay {1}. When you do, choose one —
• Create a 4/4 white and blue Elemental creature token.
• Put a +1/+1 counter on each creature you control.
• Scry 2, then draw a card.

Urdnan, Dromoka Warrior

When Urdnan enters, put a +1/+1 counter on target creature.
Whenever you attack, target attacking creature with a +1/+1 counter on it gains first strike until end of turn. If that creature has two or more +1/+1 counters on it, it gains double strike until end of turn instead.

Tomik, Distinguished Advokist

Flying
Lands on the battlefield and land cards in graveyards can't be the targets of spells or abilities your opponents control.
Your opponents can't play land cards from graveyards.

Omniscience // Omniscience

Omniscience

You may cast spells from your hand without paying their mana costs.

Karmic Justice // Karmic Justice

Karmic Justice

Whenever a spell or ability an opponent controls destroys a noncreature permanent you control, you may destroy target permanent that opponent controls.